4)
Name (s) _ _ _ _ _
General Physics --I--~~'f__---=--\_______.3I!~f_____!I.--N'
--'----""'l~"""". _ _ _ _ _ Hr.
Here are your equations: How fast:
V f = Vi
+(a)(t) (tl
*~~::~::~::~~~:~~-:~~:;f-\]-i.---:l-:----'-~~~~:~:-:~:~:~:l::~
2
How far: ~x = Vi + 1/2 (a)(t )
from the ground with a speed o~ How hig
l\l,5S
:answ~r,~approx. ~m~i~s):: \It
Y;;
o
.~
.
\ .
\~ ~.
Y' ~f\yr
.
shooting up its hot water
ill the water travel? (Neglect any air resistance.)
. ,
V.f :: V I -t 0. L-t)
~ . ~ J 1-0 ~t4itl
FM N"" . .l .I-"b­
-r
~ ~
K{4,Cf; ~ .,g,
6..X-=- 23S.L - 1\"1. b~1
~ X -= \ \ 1-" 5 '-­
-1- "
"t.-. 4 . ~
fJ.U./
2. A baby blue jay sits in a tall tree awaiting the arrival of its dinner. As the mother lands on the nest, she
drops a wriggling worm towards the hun ry chick's mouth.
wever, the worm misses the chick's mouth
and falls from the nest to the ground in 1.5 secon . Ho high' up .s the nest? (Neglect any air
resistance. )
V g -::;..·
\\
(answer = approx 1.,0"m)
3. George, the giraffe, who stand 6 meters 11, bites a branch off a tree to chew on the leaves. After the
leaves are masticated, George spits t e ranch from his mouth. If the branch has an initial speed of
approximately 0 mls and we neglect air resistance, how long (in seconds) does it take the branch to hit the
ground?
0, V I ~ OY""{ So.
(answer = 1.1 seconds)
General Physics: Preparation for quiz 3-3, Free Fall, p. 1, 10/5/2013
::
\J l +-O (,-)
1. A penny is released from rest and travels down in free fall for five seconds. How far will it travel
during this time interval? (neglect air resistance) (Answer = -122.5 m)
IIY
( -1-2-­
6.X -:/\
v ( ..-~ \
L1X
= Xf =
1
~ 2.S
I
meters
_-
.
o,p_j
"""=--~
2. What is the a1?,o, ~, T~ef,.elmY'~
, "
v,e~
, oc·ty at th~
, end of five seconds? (Answer =
!~~J~./"\ -t ~ L~ 1
49 m/s)
- \gu .
::;.,.....~
-..- ICI
I~
velocity =
-
mls _
3. In the early 1970's a famous free iall
experiment was carried out on the moon. Let's
say we do a similar experiment on Mars. On
Mars, the acceleration due to gravity (g) is -3.7
m/s A 2 while on Earth, "g" = -9.8 m/s A 2 and on
the moon, "g" = -1.6 m/s A 2
Let's say the astronaut drops the r'"
h~ r (from
rest) from a height of 1 meter orl Mars.
I
~
-~
~h~e~ fall I meter? (answer = 0.735 sec)
.
-"
_
¥ "
~\
IV
.
._ . -;
-t:::- 0
<712 -1'
2-(-'~ .-j)
b. How fast would the hammer be traveling
~3:'- ~
hen it hit the ground? (answer = -2.72 m/s)
i'
(,-,'"J ~(
·
General Physics: Preparation for quiz 3-3, Free Fall, p. 2, 10/5/2013
Here are your equations: How fast: Vf= Vi +(a)(t) How far: L\x = viet) + 1/2 (a)(t2) For free fall, a is symbolized as 'g' the acceleration due to gravity. On the earth 'g' is -9.8 mlsls but 'g' changes to other values depending upon which planet or moon you are on.
--------------------------------------------------------------.-ZX--------------------- .
wra~
, Gmete~mpire
4. King Kong carries Fay
e
State Building. At the top of the skyscraper,
Fay's shoe falls from her foot rom re t in an approximate free fall motion.
,:::-0
a) If you could time the shoe's fall , what would a stopwatch say? ~answer
- 8..1 s. ec):f!/
b.X=-
T-Lt>tf"
I
- 3, 2-\ -::
.
~
~ [ - q, 8) t
?-
b) What fast would the shoe be travelling when it hits the ground? (answer = -79.4
.
'
(2--)
t-;..~,
I
~s) ~
V:;.y{+a{t)
J : _CJ,g(~r/)
5. In the Wizard of Oz, Dorthy awakens in Munchkinlan
her house has been blown by a tornado.
If the house fell on the Wicked Witch with a velocit
- 00 mls how high above the ground did the
tornado lift the house? Assume the house starts om res at HilS altitude, falls freely, and n
ct any air
resistance.
-.
(answer = appro x 510 m)
1"u,-ta[f) - lOr) :. 0 - 71 r({;)
f, -;. . fO ,2
~
General Physics: Practice with Free Fall problems, Free Fall, p. 3, 10/5/2013
-
.
~
"f..~Jim, standing on a 10 meter high cliff, threw 'an apple up straight up into the air with an initial velocity
of20 m/s. The apple' s velocity decreased on its journey upward until at the apex (top of its path) its
velocity = 0 m/s. (neglect air resistance)
c
a) how long did the motion up to the apex take in seconds?
t ';e ~I O~
Time = _ _ _ _ _ seconds (answer = 2.04 seconds)
b) How far did the apple move upward before gravity stopped its motion (distance from ledge to apex)?
U
y-
•
\j
1
~
-'
\
L-_O__t_G{--i--__ meters (Answer = 20.4 m)
.
Distance from ledge to apex = _ _
c) Once the apple is at the apex, it falls back down towards Earth. If it clears the cliff, how far will it
travel before it hits the ground?
Distance from apex to ground =
1-0,t{
k
meters (Answer = 20.4 + 10 = 30.4 n1)
ex to the ground?
,
~
1' ~
.i
-J0 1 ~
--
,
.,. ,..
I •
.
~ -:;.
Time = _ ...._/ ---.:,,'--
1_,
{-,­
. ----'-_ _ _
seconds (Answer = 2.49 seconds)
,.
e) How fast will the apple be traveling when it hits the ground?
l
-­- -
Speed = _______ m/s (Answer = -24.4 m/s)
E==:
General Physics: Pt:eparatioD for..qpi;;?j ;"3 , Free Fall, p.:A 10/5/2013
~ \,
I