Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
Physics Pholk Song
Assignments
by
Priscilla Laws
Partially Funded by
Permission is granted by songwriters and the author of the assignments to use these
materials for non-commercial educational use only.
1
Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
1. The Bricklayer’s
Song
by Pat Cooksey
©Celtic Music, Lincolnshire, England
Originally titled "The Sick Note" and known by many other titles.
All rights reserved. International Copyright Secured. Used by Permission.
NB: With all apologies to Pat Cooksey, we'll take credit and/or blame for having composed the last verse to
this otherwise exceptional song. --David & Ginger Hildebrand
Dear sir I write this note to you to tell you of my plight,
For at the time of writing it I'm not a pretty sight.
My body is all black and blue, my face a deathly grey,
And I write this note to say why I am not at work today.
While working on the fourteenth floor some bricks I had to clear,
But tossing them down from such a height was not a good idea.
The foreman wasn't very pleased--he is a rigid hack,
And he said I had to cart them down the ladder on my back.
Well, clearing all these bricks by hand, it was so very slow,
So I hoisted up a barrel and secured the rope below.
But in my haste to do the job I was too blind to see
That a barrel full of building bricks was heavier than me.
And so when I untied the rope the barrel fell like lead,
And clinging tightly to the rope I started up instead.
I shot up like a rocket and to my dismay I found
That halfway up I met the bloody barrel coming down.
Well the barrel broke my shoulder as to the ground it sped,
And when I reached the top I banged the pulley with my head.
But I clung on tightly numb with shock from this almighty blow,
While the barrel spilled out half its bricks some 14 floors below.
Now when these bricks had fallen from the barrel to the floor,
I then outweighed the barrel and so started down once more.
But I clung on tightly to the rope, my body racked with pain,
And halfway down I met the bloody barrel once again.
The force of this collision halfway down the office block,
Caused multiple abrasions and a nasty case of shock.
But I clung on tightly to the rope as I fell towards the ground,
And I landed on the broken bricks the barrel had scattered `round.
Well as I lay there on the floor I thought I'd passed the worst,
but the barrel hit the pulley wheel and then the bottom burst.
A shower of bricks rained down on me; I didn't have a hope
As I lay there bleeding on the ground I let go of the bloody rope.
The barrel now being heavier it started down once more.
It landed right across me as I lay there on the floor.
It broke three ribs and my left arm and I can only say
I hope you'll understand why I am not at work today.
Now the moral of my story it is awfully plain to see:
That physics is a class that would have been some help to me.
So study all your lessons well and think before you act,
Or you'll run the risk of suffering from your own mistakes' impact.
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Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
(1) Bricklayer’s Song Assignment
(1) Refer to the words of the Bricklayer's Song. Assuming there is no friction in the bricklayer's pulley and rope
system, estimate the total amount of time that elapses during the injurious events described by the poor
bricklayer in the song. (2) If friction were considered, what effect would this have on your estimated time?
Would the actual time be smaller, larger or the same as the one you estimated?
To the instructor: Students in a typical physics class may need one or more of the following hints to get
started. Hints: (1) To make this estimate you need to figure out approximate values for the height of the
building, the mass of the bricklayer, and the mass of the bricks and the barrel. Then, you will need to use the
Atwood's equation; (2) Although your answer should be similar to that obtained by others, there is no single
"right" answer as you are being asked to make reasonable estimates; (3) You’ll need to use the Atwood’s
equation to determine the Bricklayer’s acceleration in each part of his journey. You cannot simply assume that
all of the bricklayer's travels occur at a = –9.8 m/s2 .
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Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
(1) Bricklayer’s Song Assignment Answers
BASIC EQUATIONS
(1) Atwood's: a =
Barrel with bricks of
mass 1.5 m = m 2
m2 - m1
ag
m1 + m2
(2) Time of fall for a constant acceleration
with no constraints:
v
Bricklayer of mass
m = m
1
y=
1 2
at
2
where y is fall distance and vo = 0, so
t=
a g = 9.8 m/s 2
2y
a
Assumptions:
(1) Height of 14th floor: y = 14 ft/floor x 14 floors = 196 ft = 64 m
(2) Initial mass of barrel with bricks m2 = 1.5 m where m1 = mass of bricklayer
(3) The barrel with brick system loses half its mass when it first hits the ground.
TIMES:
1. Bricklayer rises/barrel falls:
a=
m2 - m1
a
m1 + m2 g
2. Bricklayer falls/half-empty barrel rises:
a2 =
.75m - m
ag = 1.4m / s 2
.75m + m
3. Bricks free fall:
t3 =
4. Barrel free falls:
t4 =
t2 =
2y
=
a2
2(64 m)
= 9.6 s
(1.4 m / s 2 )
2y
= 3.6 s
ag
2y
= 3.6 s
ag
d
t=
Ât
2
t =1
Approximate Total Time: t = 8.0s + 9.6s + 3.6s + 3.6s
t @ 25s
(2) If friction were considered, what effect would this have on your estimated time? Would the actual time be
smaller, larger, or the same as the one you estimated?
ANSWER: Friction will make the times longer, the speed slower, and the injuries milder.
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Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
2. Applesauce
words and music by Jan Harmon
copyright 1988 Scott Prentice (www.HarmonPublishing.com)
Used By Permission.
CHORUS: OH GOSH! It's a McIntosh!
Squash it into applesauce,
Golden Delicious, with dapples . .
Northern Spy, Granny Smiths,
lip-smackin' pippins with cheese . .
How do you like them apples?
1.
Isaac Newton took a nap, well,
at least until that apple fell
and struck him on his cranial cavity.
He sat up and screamed,
"By gum . . it's a GRAVENSTEIN!"
But, everybody thought he said . . GRAVITY!
CHORUS
2.
Johnny Appleseed succeeded in seeding apple seeds.
From sea to sea, that he succeeded you can still see!
You can sip cider thru a straw,
but, don't sit under the apple tree
with anybody else but me!
CHORUS
3.
Now . . . APPLE's a computer, and it couldn't be cuter!
There's a menu for every APPLE appetite.
Why there’s even software for APPLE pi-R-squared.
So, cook some up, and have a little gigabyte!
CHORUS
4.
In Eden, Eve and Adam perceived their anatomies
As pure as nuns in a chapel . .
'til a pippin she was nibblin' labeled Eve evil . . .
BUT HECK! It was Adam's. . . apple!
CHORUS
5.
After serving him the streudel, William Tell said to Jubal,
"Won't you let me shoot this apple off your noodle?"
So . . aiming for the fruit . .
an arrow Will did shoot . .
but he shot him in the streudel . .
TOODLE-DOODLE!
CHORUS
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Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
(2) Applesauce Assignment
(1) How many varieties of apples you might pick off apple trees are named in the song? List them.
(2) What kind of “apple” mentioned is primarily inorganic?
(3) Which “apple” would you eat if you were a cannibal?
(4) Which “apple” is a play on words that renders it a concept?
(2) Applesauce Assignment Answers
(1)
(2)
(3)
(4)
6: Macintosh, Golden Delicious, Northern Spy, Granny Smith, pippin, and Gravenstein.
The Apple computer
An Adam’s apple
Newton’s Gravenstein = gravity.
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Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
3. Pool Table
Physics Lab Rap
words copyright 1996 Robert A. Morse
Used By Permission.
music copyright 1997 David Hildebrand (BMI)
1. One day when I was chillin' in the physics laboratory,
The professor started tellin' a momentum story.
With two balls of equal mass, prof was telling us a fable
About how they collide on an ideal pool table.
Now the energy's conserved when you add up the sum
Of kinetic and potential, so you know that ain't so dumb.
Prof said you take the cue ball and hit it with the cue,
And smash it at the 8-ball just to see what they will do.
You don't use no english; you gotta hit it straight,
And watch it do a number on that ball number eight.
But how fast and which direction will the 8-ball go,
If it’s hit head-on by the cue ball, do ya know?
What speed does the 8-ball have rollin' on the slate,
Compared to the cue ball in its pre-collision state?
Chorus: In this pool game no energy is lost.
The kinetic gets passed when the balls' paths cross.
2. The principle here is that momentum stays the same
As the cue ball had when it entered the game.
If the 8-ball goes right when it's hit real deft,
The cue ball's gotta move off to the left.
If the cue ball and the 8-ball roll at just the same speed,
What's the angle between `em? What indeed?
And after this collision where does each ball head
(In a frictionless world, just like the prof said)?
Whatever, whichever way the billiard balls go,
Momentum and energy are all ya gotta know.
Chorus: When the ball's go bang, their momenta can change
But the total of their vectors has to stay the same
3. To try this out for real you gotta find a pool table;
Put the 8-ball on the spot just as neatly as you're able.
Now the cue ball hits the eight and gives that ball a thumper,
And you mark where the two balls collide with a bumper.
You take a protractor, find the angle of each path,
Then you can do some real vector math.
When you've marked down the vector, spot the 8-ball again,
And do some more collisions until you got ten.
Collect a bunch of data and draw the vectors too
On a neat sheet of paper for the prof to review.
With a list of the angles, which you can then compare
To see how off they are from being square.
You write up your results based on the world that's real,
And tell how close they come to Newton’s ideal.
With timers and cameras we could make this real cool,
But to heck with that, let's just go play some pool!
7
Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
(3) Pool Table Lab Rap Assignment:
(1) Answer the questions posed in verse 1
(2) Answer the questions posed in verse 2
(3) Do the experiment described in verse 3.
(3) Pool Table Lab Rap Answers:
(1) Verse 1 asks what happens when a cue ball hits an 8-ball having the same mass head on.
Momentum conservation requires the cue ball come to a dead stop and the 8-ball move in the
same direction as the original cue ball was moving with the same speed as the cue ball had.
This is a momentum transfer from one ball to the other.
(2) Verse 2 asks what happens when the cue ball hits the 8-ball with the same mass in such a
way that they go off at the same speed. By applying conservation of mechanical energy and
momentum equations, one finds that the angle between the two balls is 90 degrees.
(3) Verse 3 asks students to find the local pool parlor and play an intelligent game of pool to
verify the theoretical predictions made in Verses 1 and 2. If you don’t have a real pool table,
check out the following websites: http://www.vrsports.com/pool2.html to download a demo of
VirtualPool for PCs (System Requirements: Windows 95, a Pentium microprocessor with 8 MB
of RAM, 12 MB of free memory [real and virtual], 4 MB free HD space, a mouse, and video and
sound cards supported by DirectX 5). Also check out http://www2.stratos.net/matmat/pool/, the
VirtualPool physics laboratory. For the Mac, go to
http://www.wizworks.com/macsoft/demo_01.html to download a demo of RealPool for the Mac
(System Requirements: a PowerMac with 16 MB of RAM, a color monitor, and Mac OS 7.5 or
higher
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Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
4. Galaxy Song
words by Eric Idle (PRS)
Music by Eric Idle and John DuPrez (PRS)
© 1983 Python [Monty] Pictures, Ltd.
Used by Permission.
1.
Just remember that you’re standing on a planet that’s evolving,
And revolving at nine hundred miles an hour,
That’s orbiting at ninety miles a second, so it’s reckoned,
A sun that is the source of all our power.
The sun and you and me and all the stars that we can see,
Are moving at a million miles a day,
in an outer spiral arm, at forty thousand miles an hour,
Of the Galaxy we call the Milky Way.
2.
Our Galaxy itself contains 100 billion stars
It’s 100, 000 light years side to side,
It bulges in the middle, 16, 000 light years thick
But out by us it’s just 3, 000 light years wide
We’re 30, 000 light years from galactic central point,
We go round every 200 million years.
And our Galaxy is only one of millions of billions
in this amazing and expanding Universe.
3.
The Universe itself keeps on expanding and expanding
In all of the directions it can whizz
As fast as it can go, at the speed of light you know,
12 million miles a minute, and that’s the fastest speed there is.
So remember when you’re feeling very small and insecure
How amazingly unlikely is your birth
And pray that there’s intelligent life somewhere up in space
Because there’s bugger all down here on Earth.
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Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
(4) The Galaxy Song Assignment
1.
This song provides a wonderful opportunity to practice expressing large numbers in scientific notation. For
example, the phrase “a hundred billion stars” can be rewritten as 100 ¥ 109 stars. Find all the other numbers
in the Galaxy Song and write them in scientific notation.
2.
In the first verse, compare the speed of the Earth’s revolution about its own axis with the speed of its orbit
around the sun. Which speed is greater? Hint: You’ll need to express the two speeds in the same units.
3.
The 6th line of the first verse describes us as moving 1 million miles a day in the outer spiral arm of our
galaxy as shown in the picture below. Check the arithmetic! How many miles an hour is this? You must
show your calculations!
Whirlpool Galaxy
M 51: This galaxy
has a similar shape to
the Milky Way.
Notice the outer spiral
arms in the upper
right and lower left
1.
Consider the end of the first verse:
(a) Draw a sketch of our Galaxy showing its overall shape, the central bulge and the outer edge. Mark
approximately how far you are along a line from the Galactic central point to the outer edge.
(b) What is the side-to-side distance in miles of our Galaxy? The distance in miles of the central bulge? The
distance in miles at the outer edge where you live?
2.
Consider the second verse. Calculate how fast the universe is expanding in miles per hour. In meters per
second.
10
Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
(4) The Galaxy Song Assignment Answers
1.
a million miles a day = 1.0 x 106 miles/day
at forty thousand miles an hour = 4.0 x 104 miles/hour
a hundred billion stars = 1.0 x 1011 stars
a hundred thousand light years = 1.0 x 105 light years
sixteen thousand light years thick = 1.6 x 103 light years
three thousand light years = 3.0 x 103 light years
thirty thousand light years = 3.0 x 104 light years
two hundred million years = 2 x 108 years
twelve million miles a minute = 1.2 x 107 miles/minute
2. The earth’s revolution speed about its axis is given as 900 miles per hour. The speed of the
Earth’s orbit around the Sun is given as 90 miles a second. Let’s convert 90 miles per second
into miles per hour:
miles
60 seconds
¥
=
second
1 minute
miles
60 minutes
5400
¥
=
minute
1 hour
90
3.24 ¥ 105 miles/hour
3.24 x 105 miles per hour is obviously much faster than 900 miles per hour!
3. distance = 1,000,000 miles
time = 24 hours
speed = distance/time = 1,000,000 miles/24 hours = 41, 667 mph.
4. Side to side distance is 100,000 light-years as shown in the diagram
1.0 ¥ 105 light - years ¥
9.46 ¥ 1020 m ¥
9.46 ¥ 1015 m
= 9.46 ¥ 1020 m
1 light - year
1 km
1 mile
= 9.46 ¥ 1017 km ¥
= 5.88 ¥ 1017 mile
1000 m
1.61 km
Distance in miles of the central bulge:
1.6 ¥ 104 light - years
1.5 ¥ 1020 m ¥
¥
9.46 ¥ 1015 m
=
1 light - year
1 km
1 mile
= 1.5 ¥ 1017 km ¥
=
1000 m
1.61 km
9.4 ¥ 1016 miles
11
Filename: PholkSongAssignments.doc
Author: Priscilla Laws
Distance in miles at outer edge:
3.0 ¥ 103 light - years ¥
2.84 ¥ 1019 m ¥
2/11/03 4:40 PM
9.46 ¥ 1015 m
=
1 light - year
1 km
1 mile
= 2.84 ¥ 1016 km ¥
=
1000 m
1.61 km
1.76 ¥ 1016 miles
5. Speed of expansion of the universe in miles per hour:
1.2 ¥ 107
miles
60 min
¥
= 7.2 ¥ 108 miles/hr
min
hr
Speed of expansion of universe in meters per second, using the miles per hour answer from
above:
miles
1.61 km
km
1000 m
¥
= 1.2 ¥ 109
¥
=
hour
1 mile
hour
1 km
miles
1 hour
1.2 ¥ 1012
¥
=
hour
3600 sec
7.2 ¥ 108
3.3 ¥ 108 miles/sec
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Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
5. Motion
Detector Rag
words & music: David Hildebrand (BMI)
copyright 1997 David Hildebrand
1. If you step back slow when the experiment is ready,
A position time-line shows an up-slope neat and clean.
But if you stop short, then does the line continue steady?
What's the shape? How's it look? Like the sample in your book?
How are your moves depicted on the screen?
You're doing the motion detector rag,
The dance that's all the rage.
You'll learn to move and expect how the graph looks
On the screen or in the printed page.
You can move backwards, forwards,
Fast or slow or in between,
Accelerate yourself, or just stand still;
Make the coolest graph that ever was seen.
2. Well it works both ways, you can move and watch the computer
Or you can see a graph, and turn the shapes into a dance
Start with a steep and steady position-time down-slope,
a gentle steady up-slope and then a flat line,
How will this make you dance? Dance the...
Motion detector,
Wiggle fingers in the air.
Where you can move and a velocity-time graph materializes
over there...
There on the screen representing direction and velocity
Forget the Waltz, Tango, Charleston,
It's the Motion Detector for me!
3. Now the interpretation of a straight horizontal line
Depends on the axis labels written on the left and below.
If an acceleration line looks flat and positive that is fine,
But what then is the shape of the velocity graph?
Or the position curve, do you know?
You gotta do the motion detector rag,
They're doing it in New York and France.
It's the multi-media graphical sport;
A hyper-scientific dance
Wherein the mind actively visualizes
As your feet move to and fro.
It's sorta like ballroom physics class, the motion detector
you know!
13
Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
(1) Refer to the motion described in the
first verse of the Motion Detector Rag.
Sketch a position vs. time graph of the
motion described if you are moving for
the same amount of time that you are
standing. Also, describe the shape of
the graph in words.
Position
(5) Motion Detector Rag Assignment
Time
Position
(2) Second Verse: Refer to the motion described
in the second verse of the Motion Detector Rag.
Sketch a position vs. time graph of the motion
described if you are moving for the same
amount of time while you are making the
“steep down-slope,” while you are making the
“gentle up-slope,” and while you are making
the flat line. Also, describe what you are doing
in words (in other words, when are you
standing still, moving away from the motion
detector, moving toward the motion detector?
Which motion is the most rapid, and so on?)
Time
Acceleration (m/s/s)
(3) Third Verse: (a) Sketch the acceleration vs.
time graph described in verse three of the Motion
Detector Rag. (b) Assuming you start from rest
and move away from the motion detector at an
acceleration of +1.0 m/s2 for 5 s, sketch the
corresponding velocity vs. time graph of your
motion. (c) Sketch the shape of the corresponding
position vs. time graph of your motion. (d)
Describe the motion in words you would need to
undergo to create the graphs you just sketched.
0
0
1
2
3
Time (seconds)
4
5
0
0
1
2
3
Time (seconds)
4
5
5
Position (m)
Velocity (m/s)
6
4
3
2
1
0
0
1
2
3
Time (seconds)
4
5
14
Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
(5) Motion Detector Rag Assignment Answers
(1) Refer to the motion described in the
first verse of the Motion Detector Rag.
Sketch a position vs. time graph of the
motion described if you are moving for
the same amount of time that you are
standing. Also, describe the shape of
the graph in words.
Position
Time
ANSWER: For the first half of the time on the graph there is a line with a relatively small
positive slope showing motion away from the motion detector at a slow steady speed and
during the second half of the motion the horizontal line indicates that I am standing still.
2) Second Verse: Refer to the motion described
in the second verse of the Motion Detector Rag.
Sketch a position vs. time graph of the motion
described if you are moving for the same
amount of time while you are making the
“steep down-slope,” while you are making the
“gentle up-slope,” and while you are making
the flat line. Also, describe what you are doing
in words (in other words, when are you
standing still, moving away from the motion
detector, moving toward the motion detector?
Which motion is the most rapid, and so on?)
Position
Time
ANSWER: For the first portion of the time I am moving rapidly toward the motion detector
creating a steep negative slope, for the second portion of the time, I am moving away from the
motion detector at a steady slow rate creating a gentle positive slope, and for the third portion
of the motion when the line becomes horizontal I am standing still.
+2
(3) Third Verse: (a) Sketch the acceleration vs.
time graph described in verse three of the Motion
+1
Detector Rag. (b) Assuming you start from rest
and move away from the2 motion detector at an
Acceleration (m/s/s)
acceleration of +1.0 m/s for 5 s, sketch the
0
corresponding velocity vs. time graph of your
motion. (c) Sketch the shape of the corresponding
-1
position vs. time graph of your motion. (d)
Describe the motion in words you would need to
-2
undergo to create the graphs you just sketched.
0
1
6
2
3
Time
(seconds)
4
5
5
4
Velocity (m/s)
Position (m)
3
2
1
0
0
0
2
3
4
5
0
1
2
3
4
5
Time
Time
(seconds)
(seconds)
ANSWER: Initially I have no velocity and then I start moving away from the motion detector
very slowly but start increasing my velocity at a steadily increasing rate of 1.0 m/s each
second. By the end of the 5 s. I should be moving at a velocity of 5.0 m/s. The shape of my
position vs. time graph should be parabolic.
1
15
Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
6. Newton’s
Laws
words copyright 1995 Bill Franklin
Used By Permission.
music copyright 1997 Ginger Hildebrand (BMI)
1. In physics there’s a law that objects moving
Keep moving until forces make them slow.
Of all the laws in the world of physics
This one you should surely know.
2. A second law was added by Sir Isaac:
Resultant force produces change; in fact,
An object changes speed or its direction
In every case, net forces act.
3. His third law deals with objects that are touching.
Well, actually they never touch, you see,
But still they push the same on one another.
How can that be? How can that be?
4. And each and every mass throughout creation
Attracts the other ones with gravity,
Decreasing with the square of separation,
A matter of Geometry.
5. This law for with Sir Isaac is most famous,
Explains the paths of planets 'round the sun,
And why the tides flow ceaselessly on beaches.
Join Earth and sky, stunned everyone.
6. Two hundred years and more these laws were tested,
In every time and place they checked out right,
Until young Einstein dared to dream of moving
As fast as light. Oh, he was bright.
7. Then Niels Bohr took a look at glowing atoms,
And could they little suns and planets be?
But found that changes they could not make smoothly
In radius, or energy.
8. And soon it seemed that chance controls electrons;
That probability rules everywhere.
'Tho Einstein never found this to his liking Does God throw dice? Doesn’t he care?
9. Today we see that Newton’s Laws stand firmly
For everything we deal with day and night,
Above the realm of atoms and electrons,
And well below the speed of light.
10. So learn them well, and they’ll solve all your problems.
Well, not all, but certainly a lot All problems you might have involving forces.
Remember well! Forget them not!
16
Filename: PholkSongAssignments.doc
Author: Priscilla Laws
2/11/03 4:40 PM
(6) Newton’s Laws Assignment
1. On the Statements of Newton’s Laws: The verses describing Newton’s Laws in this song are suggestive of
them, but certainly not complete scientific statements.
(a) Give complete statements of Newton’s First and Second Laws.
(b) Look at the first verse of the song. Use your statements of Newton’s first two laws to explain whether or not
forces acting on a moving object can serve to make it slow down. If so, what direction does the slowing force
have to act?
(c) Look at the first verse of the song. Use your statements of Newton’s first two laws to explain whether or not
forces acting on a moving object will always make it slow down. If not, in what other ways can forces change
the motion of an object?
(d) Give a complete statement of Newton’s Third Law.
(e) The statements in the third verse of the song that suggests that the Third Law is about objects that are
touching but “well actually they never touch.” These statements seem contradictory. If you know something
about electrostatic forces (Coulomb forces), explain what the songwriter might have meant by these statements.
(f) Which two of Newton’s three laws of motion describe the action of forces on a single object? Which one of
them is about the forces of interaction between two objects? Explain what clues in the verses of the song
support your answer.
2. On Einstein and Bohr: Verses six through nine are about modern physics.
(a) Look at the sixth verse of the song. Read about the major assumptions of Einstein in developing his theory
of special relativity. What did Einstein assume about the way light moves according to different observers who
are moving together or apart at a constant velocity?
(b) Look at the seventh verse of the song. Read about the major assumptions of Bohr in developing his theory
of the atom. What did Bohr assume about the radii and the energies an electron orbiting an atomic nucleus can
have?
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(6) Newton’s Laws Assignment Answers
1. (a) There are many equivalent statements of Newton’s Laws. The statements that follow
are not the only ones.
FIRST LAW: A body at rest or moving at a constant velocity will remain at rest or will continue
to move at the same constant velocity unless acted upon by a net force. (The term net refers
to the sum of all the forces acting on a body.) Newton’s First Law seems unbelievable because
in most every day situations objects set in motion tend to slow down and come to rest.
Physicists believe that in most everyday situations, objects have friction forces acting on them
that are often hidden from view.
SECOND LAW: A body that experiences a net force will undergo an acceleration proportional
to the net force. The amount of the acceleration also depends on the mass of the object and
is inversely proportional to that force and smaller when the mass is larger. Mathematically the
relationship between force, mass, and acceleration can be summarized by the equation: net
force = mass ¥ acceleration.
(b) Yes, a force that acts in a direction opposite to the motion of a body can cause it to slow
down.
(c) If a force acts at right angles to a moving body, the body will change its path and have a
component of its motion in the direction of the net force acting on it. A force acting in the
direction of a body’s motion can cause it to speed up.
(d) There are many equivalent statements of Newton’s Third Law. The statement that follows is
not the only acceptable one.
THIRD LAW: Any two bodies that interact will exert forces on each other at any particular
moment that are equal in magnitude and opposite in direction.
(e) When most everyday bodies are very close to each other they appear to collide or touch
each other. Most physicists believe that ordinary bodies that are quite close interact very
strongly as a result of repulsive electrostatic forces between electrons that surround the atomic
nuclei in the bodies. These electrostatic interactions are believed to be action-at-a-distance
forces. So the bodies appear to be touching but are thought to be separated by distances too
small to see with the naked eye.
(f) According to the statements given here of the three laws, the first two laws describe the
experience of a single body in the presence or absence of forces. The third laws describes
forces experienced by two bodies that are interacting with each other.
2(a) In formulating his theory of relativity, Einstein was interested in describing the laws of
physics in reference frames that move at constant velocities with respect to each other. For
example, suppose a rocket ship is moving away from an asteroid in a straight line at a
constant speed. Someone in the rocket ship would be in one reference frame and someone
on the asteroid would be in another reference frame. Einstein made the following assumptions
about these kinds of reference frames:
1.
2.
3.
The Laws of Physics will appear to be the same in both reference frames.
When observers in both reference frames look at the same light beam they will
each conclude it is moving at the same speed. (This assumption seems
unbelievable but it works!)
It is impossible for any material object to move at the speed of light.
(b) Bohr thought of electrons as orbiting around atomic nuclei in roughly circular orbits in much
the same way as the Earth orbits the Sun. He made the assumption that there were only
certain possible combinations of orbital radius and speed. Basically, he postulated that the
angular momentum of an orbiting electron (which is the product of the mass of the electron, its
radius of orbit, and its speed) must be an integer multiplied by a constant known as h-bar. This
means that there are only certain orbital radii and certain energies that an electron orbiting an
atom can have.
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7. I’m my Own
Grandpaw
by Dwight Latham and Moe Jaffe
copyright 1947, RENEWED 1975 COLGEMS-EMI MUSIC, INC. (ASCAP)
All Rights Reserved. International Copyright Secured.
Used By Permission.
1. Many, many years ago when I was twenty-three,
I got married to a widow who was pretty as can be.
This widow had a grown-up daughter who had hair of red;
My father fell in love with her and soon the two were wed.
2. This made my dad my son-in-law and changed my very life.
My daughter was my mother 'cause she was my father's wife.
And to complicate the matter even though it brought me joy,
I soon became the father of a bouncing baby boy.
3. This little baby then became a brother-in-law to Dad,
And so he is my uncle even though it makes me sad,
'Cause if he is my uncle then that also makes him brother
To the widow's lovely daughter who of course is my stepmother.
4. Father's wife then had a child which kept them on the run,
And he became my grandchild 'cause he was my daughter's son.
My wife she is my mother's mother and it makes me blue,
'Cause even though she is my wife she's my grandmother too.
5. Now if she is my grandmother then I am her grandchild,
And every time I think of it, it nearly drives me wild.
'Cause now I have become the strangest case you ever saw,
As husband to my grandmother I am my own grandpaw.
6. Oh, I'm my own grandpaw, I'm my own grandpaw,
It sounds funny I know, but it really is so,
I'm my own grandpaw.
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(7) I’m My Own Grandpaw Assignments
Unless you’re a genius, it’s impossible to check out the logic of this preposterous state of affairs while listening
to the song. The music and rhymes are distracting and the words roll by terribly fast. Study the words of the
song shown above and do the following:
(1) Devise a chart or other visual representation depicting the relationships between the various characters in the
song. Use it to convince yourself and others either that the guy singing the song is or is not his own grandpa.
(2) Sharpen your pencil and write a song with a new cast of characters in it entitled I’m My Own Grandma.
NOTE TO INSTRUCTORS: If you feel your students need a hand at organizing their listening, you might give
them an analysis tool chart as an aid. A chart like the one shown below can help students map out the various
relationships described in the song.
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(7) I’m My Own Grandpaw Answers
Answer: (1) In the “answer” chart, we’ve used lines with arrows to depict blood relationships
and lines without arrows to depict “step” relationships.
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8. Particles...
Quant’em
words and music by Jan Harmon
copyright 1995 Scott Prentice
(www.HarmonPublishing.com)
Used by Permission.
Oh, let us sing of particles
and fluctuations quantum...
Of leptons, quarks and antiquarks,
'cause whether or not we want 'em,
they are the stuff of nothingness
of which what they aren't...
we're 'em!
So … three cheers for Neutrinos!!
(Tho we cannot see or hear 'em!)
Oh, ... [repeat as a round]
Computer models of carbon monoxide (blue)
and borane , BH3, (red).
(8) Particles. . .Quantum Assignment
1.
Look up the characteristics of the following particles or types of particles and describe them:
(a)
(b)
(c)
(d)
leptons
quarks
antiquarks
neutrinos
2. What would happen if a quark and an anti-quark came together in empty space?
(8) Particles. . .Quantum Assignment Answers
1 (a) Leptons are a group of particles found in the nucleus of atoms. Electrons are one kind of
lepton. Leptons do not interact strongly with other kinds of particles. (b) Quarks are small
particles that make up protons and neutrons. Quarks have the properties of “up,” “down,”
“strange,” “charm,” “top,” and “bottom.” (c) Antiquarks have the same mass as quarks, but
opposite electric charge. (d) Neutrinos are particles with no mass or charge, which travel at the
speed of light. They are emitted during beta decay reactions.
2. A quark and an antiquark would annihilate each other and the energy they originally had
would be carried off by two gamma rays.
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9. Electricity and
History
words & music copyright 1997 Ginger Hildebrand (BMI)
Franklin made a kite with some silk and a key
To test the stormy discharge of electricity.
Allesandro Volta made the battery first,
And readied all the world for an invention burst.
Ampere and Oersted electromagnetism found
So that Faraday with transformer could leap and bound.
Tesla, what a guy, made a Tesla Coil
To transmit energy and make your water boil.
60 K frequency's a safer wave,
but the noise sent the coil to an early grave.
Now they use it sending waves of radio,
Think of Tesla when you hear my song in stereo.
Edison gave the world the incandescent ball,
Envisioned direct current to light us all.
But Tesla's alternating current saved the dayVacuum's good for bulbs but in work won't pay.
Phonograph and moving pictures, telegraph tooAll made Edison better than me and you.
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(9) Electricity and History Assignment
(1) Many scientists who are no longer living contributed to our current understanding of electricity and
magnetism. Do a little research and find out more about the lives and work of one or more of the following
scientists: Franklin, Volta, Ampere, Oerstad, Tesla, Edison. When and where was each one born? Write a brief
sentence or two about what each scientist studied or invented that involved electricity. Be sure to cite your
sources of information. If you use the Internet, cite the URL of the website that contained the information on
each of the scientists.
(2) Pick one of the scientists and write a two-page essay about one of his major contributions to our
understanding of electricity and magnetism. You will probably want to use a good history of science book in
conjunction with principles described in your text book to complete this part of the assignment.
(9) Electricity and History Assignment Answers
(1) Benjamin Franklin invented the lightning rod. He was born in Boston in 1706. Alessandro
Volta invented the voltaic cell, a precursor to today’s battery. He was born in Italy in 1745.
Andre Ampére was born in France in 1745. Ampere discovered the left and right-hand rules of
a magnetic field around a current-carrying wire. Hans Christian Oersted discovered
electromagnetic energy when he observed a magnetic needle being deflected by a conductor
carrying a current. He was born in Denmark in 1777. Nikolai Tesla, born in 1856 in Croatia,
discovered alternating current, and invented devices which allowed the development of radio
and electricity. Thomas Edison was born in 1847 in Ohio. He invented the microphone, the
record player, the incandescent lamp, and the electrical distribution center which enabled
electricity to be used in homes and buildings.
Some references: The Encyclopedia Britannica; Microsoft Bookshelf CD-ROM; The
Discoverers, by Daniel J. Boorstin, Random House, 1983; The Great Physicists from Galileo to
Einstein, George Gamow, Dover Publications, 1961.
(2) More references:
Milestones in Science and Technology: The Ready Reference Guide to Discoveries,
Inventions, and Facts, by Ellis Mount and Barbara A. List, Onyx Publishers, January 1994.
Timetables of Science: A Chronology of the Most Important People and Events in the History
of Science, by Alexander Hellemans, Brian Bunch, and Bryan Bunch, Touchstone Books,
March 1991.
The History of Electricity, by Robert Snedden, Thomson Learning, May 1995.
Scientists who Changed the World, Phillip Wilkinson and Michael Pollard, Chelsea House
Publishers, June 1994.
Andre-Marie Ampére, James P. Hoffman, Cambridge University Press, May 1996. (The only
biography of Ampere available in English.)
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10. How Colors
Delight
words copyright 1994 Judy Franklin
Used By Permission.
music copyright 1997 Ginger Hildebrand (BMI)
Oh, do you remember how colors of light
Can be added together to please and delight?
Cyan is exotic, no doubt that is true,
But it's only the mixing of plain green and blue.
Magenta is wild and romantic, it's said,
But its parents are simple; they're just blue and red.
And yellow is sunshine and lemony clean,
Thorough the judicious mixing of pure red and green.
Now black is the absence of reflected light,
But when all come together the mixture is white,
When it's light we are mixing the fact can be seen,
That the primary colors are red, blue, and green.
The rainbow is sunlight that boldly displays
The spectrum of color in its arching rays.
And now you remember how colors of light
Can be added together to please and delight.
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(10) How Colors Delight Assignment
1.
Suppose three beams of light of different colors overlap as shown in the following diagram:
According to the song, what colors will appear in each of the places where the beams overlap?
2.
3.
Here’s a tricky question. Suppose a magenta beam and a yellow beam are shining through a filter so all the
red light present in the two beams is removed. What is the color of the light that leaves the filter?
(10) How Colors Delight Answers
1. In section 1 on the diagram, the light will be magenta. In section two, the light will be yellow.
In section three, the light will be cyan. In section 4, the light will be white.
2. Since magenta is made up of blue and red light, the red will be filtered, leaving behind the
blue light. Yellow is made up of red and green light, so only the green light will pass
through the filter. The blue light and the green light will combine to make cyan.
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11. Simple
Harmonic
Oscillator Rap
words copyright 1986 Scott Lewicki, David
Politzer, and Doug Priest
Used by Permission.
1. I want to talk today about things that shake,
And I hope my words aren't too opaque.
One degree of freedom moving to and fro,
Just how it moves, we'd like to know.
We can represent all kinds of things
By a single mass between ideal springs.
Each spring's connected to a wall.
So the outer ends don't move at all.
2. Let the mass be m, spring constant k,
But don't let friction get in the way.
Use Newton's Laws, and wadda we got?
F equals m psi double dot.
F is also minus k psi times two.
So now we have a diff E Q.
And we can write down the general solution
For the simple harmonic time evolution.
3. Let omega be root two k over m.
Here's the answer. Won't repeat again.
Psi is A cosine omega t
Plus a phase. Call it phi.
So it's all very simple. And you can see,
For any initial psi and velocity,
We can find the constants A and phi.
And the equation's exact for all time t.
4. Now look again at the diff E Q.
It's homogeneous and linear, too.
So if you add two solutions together,
Their sum's a solution that's even better.
We call it the principle of superposition.
You can use it to fit the boundary condition.
In fact, there is no contradiction
If we use it in a system that does have friction.
5. In a real system (nothing's perfect, of course)
We have to include the frictional force.
Suppose it goes as the velocity.
Write minus m gamma d psi d t.
Now if the damping is not too strong,
Our old solution is close but wrong.
See, it starts out with some amplitude A,
But after a while it just dies away.
6. The amplitude decays exponentially,
As you can see experimentally,
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As e to the minus half gamma t.
Now, it's almost right, but you see
The frequency is lower as we can compute.
Omega is now given by square root
Of the quantity k over m times two
Minus quarter gamma squared, and now we're through.
7. So now we have the complete solution
For an oscillator's time evolution.
And when there's damping, as everyone knows,
The amplitude decays, and the frequency slows.
If we have two solutions, no matter how chose,
You know we can always superpose.
And since you all find physics such fun,
Do problems twelve, eighteen, and twenty one.
Class dismissed.
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(11) Simple Harmonic Oscillator Rap Assignment
Listen carefully to the song or read the words. The words are not complete enough to allow you to tell exactly
how the equations mentioned are written without understanding the mathematics of damped harmonic motion.
That is, the rap words, as sung, lack verbal parentheses. Thus you should combine your physics knowledge
with the words to express the equations in the notation used by the song’s composers.
1. According to verse 2, what is the differential equation describing Simple Harmonic Oscillation?
2. According to verse 3, what’s the differential equation for omega (w)? What is the equation for psi (y)?
3. According to verse 5, what is the new differential equation with damping (a “frictional force”) present?
4. According to verses 5 and 6, what is the new equation for psi with damping present? What is the new
equation for omega?
(11) Simple Harmonic Oscillator Rap Assignment
1.
 F = -2ky = my˙˙
2k
m
y = A cos(wt + j)
2. w =
3.
 F = -2ky - mg dy
dt
4. w =
2k g 2
m
4
g
y = Ae
-2t
cos(wt + j)
where
ÂF
is the net force on the object that is oscillating
k is the spring constant for one spring
m is the mass of the oscillating object
g is the damping constant per unit mass
w is the angular frequency of the oscillation.
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Answers
Filename: PholkSongAssignments.doc
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12. To Sir Isaac
words copyright 1997 David Hildebrand (BMI)
melody: traditional
T'was sixteen hundred forty-two in Lincolnshire, you see,
When on this earth was born a boy perplexed by gravity.
Both light and motion held his thoughts as did the stars and earth;
Young Isaac contemplated things from the moment of his birth.
T'was granny brought the young lad up, at 19 years he swore
At Cambridge to bask in the light of others gone before-Descartes and Boyle and Galileo, Aristotle too,
Absorbing genius of the past, re-casting it anew.
T'was there at University such eagerness he'd shown,
‘Till plague closed down those sacred halls and left him on his own.
Through 18 months sequestered off from others' thoughts he stewed
And made those monster, bombshell thoughts and theories which ensued.
With pendulum and telescope and prism oft played he,
Trying o'er and o'er to find the truth in what may be
The force that holds us to the ground and makes the apple drop-A thing that hardly matters unless this law should stop.
Now let me not distort the truth of Newton all the while.
His optics had a finite need with Hooke to reconcile.
At times he unified the work of great minds gone before,
And at other times, distracted, lost, he knocked at the wrong door.
Perhaps that's why when fifty years of age his nerves did fail.
His fame allowed him wealth and ease but his mind was turning frail.
Though knighted by the good Queen Anne in 1708,
For nearly twenty years beyond, his mind would vegetate.
So let's all raise a glass to youth, its curious probing mind,
Its urge to make some logic of the stranger truths we find.
As born when Rembrandt held a brush and dead when Bach composed,
Sir Isaac's universal mind changed his'try, then reposed.
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(12) The Sir Isaac Assignment
1. Historians do not always agree on facts. (a) Look up information about Isaac Newton’s Life and write a short
essay summarizing the highlights. Cite the source or sources you have used. (b) Discuss which “facts” agree
with those in the song and which ones, if any, are reported differently in your sources.
(12) The Sir Isaac Assignment Answers
A great website for finding information about Newton is http://wwwcn.cern.ch/%7Emcnab/n/
1a.) A sample essay:
Isaac Newton was born on January 4, 1643 [see 1b. below], at Woolsthorpe in Lincolnshire,
England. After his widowed mother remarried when he was three, Newton was raised by his
grandmother. Newton began attending Trinity College at the University of Cambridge in 1661,
and received his bachelor’s degree in 1665. The university closed down for 2 years due to an
outbreak of the plague. In 1668, Newton received his master’s degree.
During the close-down of Cambridge, in the autumn of 1666, Newton invented a new kind of
mathematics, which we know as calculus. However, he did not try to introduce it to the field of
mathematics since he was fearful of criticism. Gottfried Leibniz, who independently came up
with calculus, introduced it in 1675. This led to an enormous conflict between Newton and
Leibniz.
Newton was the first person to theorize sunlight is a blend of different-colored rays, and
demonstrated this by passing sunlight through a prism. The resulting rainbow proved his
theory. Between 1684 and 1687, Newton formulated his three laws of motion and derived the
law of universal gravitation. He published this theory in the book Philosophiae Naturalis
Principia Mathematica. After the publication of this book, Newton was accused of plagiarism by
the physicist Robert Hooke. It is generally believed that Hooke’s claim is incorrect.
In 1693, Newton suffered from a nervous condition, and after recovering from it, never again
made any brilliant discoveries or scientific breakthroughs. According to Richard Westfall, he
was knighted in 1705 by Queen Anne. Newton died in 1727.
Info obtained from Robert Westfall’s biography of Isaac Newton at:
http://www.newton.cam.ac.uk/newtlife.html.
1b.) According to Richard Westfall, one of Newton’s leading biographers, Newton was born
early on Christmas Day in 1642. Many biographers list his birth date as January 4th, 1643. This
discrepancy is explained by the fact the English considered the Pope’s modification of the
Gregorian calendar to be wrong. So at this time, dates on the English calendar were ten days
earlier than dates on the European continent. Thus, Christmas Day in 1642 in England was
January 4th, 1643 in Europe. Also, Newton was 18.5 when he started attending Cambridge,
not 19. He was knighted in 1705, not 1708. (But then, “1708” rhymes better with “vegetate.”)
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13. Elements
© 1959 Tom Lehrer (ASCAP)
performance (p) 1959 from the CD, “Songs and
More Songs by Tom Lehrer"
Used By Permission of Tom Lehrer
1. There's antimony, arsenic, aluminum, selenium,
And hydrogen and oxygen and nitrogen and rhenium,
And nickel, neodymium, neptunium, germanium,
And iron, americium, ruthenium, uranium,
Europium, zirconium, lutetium, vanadium,
And lanthanum and osmium and astatine and radium,
And gold, protactinium and indium and gallium,
And iodine and thorium and thulium and thallium.
2. There's yttrium, ytterbium, actinium, rubidium,
And boron, gadolinium, niobium, iridium,
There's strontium and silicon and silver and samarium,
And bismuth, bromine, lithium, beryllium, and barium.
3. There's holmium and helium and hafnium and erbium,
And phosphorus and francium and fluorine and terbium,
And manganese and mercury, molybdenum, magnesium,
Dysprosium and scandium and cerium and caesium.
And lead, praseodymium and platinum, plutonium,
Palladium, promethium, potassium, polonium,
And tantalum, technetium, titanium, tellurium,
And cadmium and calcium and chromium and curium.
3. There's sulfur, californium and fermium, berkelium,
And also mendelevium, einsteinium, nobelium,
And argon, krypton, neon, radon, xenon, zinc and rhodium,
And chlorine, carbon, cobalt, copper, tungsten, tin and sodium.
These are the only ones of which the news has come to Ha’vard,
And there may be many others but they haven't been discavard.
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(13) Elements Assignment
(a) Examine a copy of the Periodic Table. What is the “lightest” element described by Tom Lehrer in the song?
What is the “heaviest” element listed?
(b) What elements, if any, are in a current periodic table that are not listed by Lehrer?
(c) Based on your answers to questions (a) and (b), estimate when the Elements Song was written.
Hint: Two good websites for finding more information about the periodic table are:
http://www.mindspring.com/~drwolfe/WWWolfe_hcc_links_ptable.htm and
http://domains.twave.net/domain/yinon/default.html
(13) Elements Assignment Answers
(a) ANSWER: The lightest element listed is hydrogen and the heaviest listed is nobelium.
(b) ANSWER: Lawrencium, unnilquadium, unnilpentium, unnilhexium, unnilseptium,
unniloctium, unnilennium, ununnilium, unununium, and ununbium.
(c) ANSWER: The heaviest element Lehrer refers to nobelium and it was discovered in 1957.
The next element discovered after that, lawrencium, was discovered in 1961. The song must
have been written between 1957 and 1961.
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14. First and
Second Law
words and music by Michael Flanders & Donald Swann
(p) © 1963 The Estates of Michael Flanders and Donald Swann
From the 1964 album "At the Drop of Another Hat", © (p) EMI
Records, Ltd.
Used by permission of the Flanders & Swann Estates 1998
Master License courtesy of EMI Records, Ltd.
The First Law of Thermodynamics:Heat is work and work is heat
Heat is work and work is heat
Very good! The Second Law of Thermodynamics:Heat cannot of itself pass from one body to a hotter body
Heat cannot of itself pass from one body to a hotter body
Heat won't pass from a cooler to a hotter
Heat won't pass from a cooler to a hotter
You can try it if you like but you'd far better notta
You can try it if you like but you'd far better notta
'Cos the cold in the cooler will get hotter as a rule-a
'Cos the cold in the cooler will get hotter as a rule-a
'Cos the hotter body's heat will pass to the cooler
'Cos the hotter body's heat will pass to the cooler
Good, First Law!
Heat is work and work is heat
And work is heat and heat is work
Heat will pass by…conduction
Heat will pass by…conduction
And heat will pass by…convection
Heat will pass by convection
And heat will pass by…radiation
Heat will pass by…radiation
And that's a physical law!
Heat is work and work's a curse
And all the heat in the Universe
Is gonna cooooool down 'cos it can't increase
Then there'll be no more work and there'll be perfect peace!
Really?
Yeah, that's entropy, man!
And its all because of the Second Law of
Thermodynamics, which lays down that…
You can't pass heat from a cooler to a hotter
Try it if you like but you far better notta
'Cos the cold in the cooler will get hotter as a rule-a
'Cos the hotter body's heat will pass to the cooler
Oh you can't pass heat, cooler to a hotter
Try it if you like but you'll only look a fool-a
'Cos the cold in the cooler will get hotter as a rule-a
And that's a physical law!
Oh, I'm hot!
Hot? That's because you've been working!
That's the First and Second Law of Thermodynamics!
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(14) Thermodynamics Assignment
Please analyze the statements in the song from the perspective of the “official doctrine” set forth in an
introductory physics course. Which, if any, appear to be correct under all circumstances, under special
circumstances only, or under no circumstances?
"Thermodynamics is simply the science of heat and work and the relationships between them as laid down in the Laws
of Thermodynamics which may be expressed in the following simple terms:
The First Law of Thermodynamics
1. Heat is work and work is heat.
The Second Law of Thermodynamics
2. Heat cannot of itself pass from one body to a hotter body.
3. Heat won't pass from a cooler to a hotter.
4. You can try it if you like but you far better notter cause the cold in the cooler will get hotter as a ruler
5. Heat is work and work is heat
6. Heat will pass by conduction
7. Heat will pass by convection
8. Heat will pass by radiation and that's a physical law
9. Heat is work and work's a curse and
10. all the heat in the universe is gonna cool down cause it can't increase
11. and then there'll be no more work and there'll be perfect peace,
12. yeah that's entropy, man and all because the second law of thermodynamics. . ."
(14) Thermodynamics Assignment Answers
Statements 1, 5 & 9 are not always true. According to the first law of thermodynamics: ?U = Q
- W where ?U represents the change of internal energy of a thermodynamic system that has
heat energy, Q, transferred to it while it does an amount of work on its surroundings W. Thus,
“Heat is work and work is heat” is only true in the case of an isothermal process for which the
temperature change and hence the change in internal energy of a thermodynamic system is
zero (?U = 0). A more correct but less snappy phrase would be “Work done by the system on
its surroundings is the heat transferred to the system plus the change in internal energy that
the system undergoes.”
In a real engine cycle, the heat energy transferred to a working medium cannot all be
transferred into useful work. This would violate the Second Law of Thermodynamics.
Statement 10 is not very meaningful in the study of physics because heat which is defined as
energy in transit or the process of energy exchange between two systems is not something
that can “cool down.” Hotter bodies (or those with higher temperatures) can only transfer heat
energy to cooler bodies--a process cannot cool down.
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