TODAY’S OUTCOMES:
SUN AND MOON
- Review and organize moon
observation activity
FORCE, MOTION AND ENERGY
- Review the interpretation of distancetime graphs; discuss inertia
- Study how forces interact between
objects
- Investigate how the height of an
inclined affects applied forces
RESPONSIBILITIES FOR THE MOON OBSERVATION:
*Both observers are responsible for doing the activity!!
WHAT EXACTLY SHOULD I DO FOR MY OBSERVATION??
THE DAY BEFORE:
Go to http://almanac.com/moon
Click “See moon rise and set times”
Your 24 hour “day” runs from
midnight to midnight
Today’s Example
RESPONSIBILITIES FOR THE MOON OBSERVATION:
*Both observers are responsible for doing the activity!!
WHAT EXACTLY SHOULD I DO FOR MY OBSERVATION??
THE DAY BEFORE:
Go to http://almanac.com/moon
Click “See moon rise and set times”
Your 24 hour“day” runs from
midnight to midnight
Tomorrow’s Example
RESPONSIBILITIES FOR THE MOON OBSERVATION:
*Both observers are responsible for doing the activity!!
WHAT EXACTLY SHOULD I DO FOR MY OBSERVATION??
THE DAY BEFORE:
Go to http://almanac.com/moon
Click “See moon rise and set times”
Your 24 hour“day” runs from
midnight to midnight
An Example of the moon setting
before it rises
THIS IS A GRADED ASSIGNMENT
10 points for the moon observation
5 points for doing your observations
5 points for turning in your daily log
IF THE SUN IS VISIBLE WHEN THE MOON IS OUT,
YOU MUST ESTIMATE THE ANGLE BETWEEN THE SUN
AND MOON!! (One fistful ≈ 10°)
DURING CLASS: When the lab starts, I’ll check
the observation sheets of the assigned
observers, THEN they can copy their diagram
to the white boards.
What if I try as hard as I can and can’t find the
moon??????
1) It is your responsibility, based on the moon
schedule, to find a good time to see the moon!
Use the moonrise/set schedule to see when the
moon is high in the sky!
Ask if you need help!
2) What if the weather is bad???
If the weather is bad all day, this is a legitimate
excuse (of course)!
*Do a make-up observation as soon as the weather
is good again for credit
3) What if the weather is good, I looked at the
right time, and I STILL can’t see the moon?
Log what time of day you looked. If the moon is
too close to the sun, it might be too tough to see!
If this is the case, and you check at an appropriate
time, you will get credit for your observation(s)!
If Dr. Straley and Brian Ray and I can all see the
moon, than so can you!
9. Draw a graph that represents this story: Dave’s route to school has three parts. At first the road is level,
and he goes about 20 mph for 15 minutes. But then there is a steep hill, and it takes him 12 minutes to get up
it, going only 6 mph. At the end, he zooms back down the hill in 2 minutes, going 30 mph.
Distance (miles)
4 6 8 10 12 14
distance = speed ✕ time
B
C
0
2
A
0
4
8
12 16
20 24 28
÷ 60 to get min. → hrs.
A. distance = 20 mi./hr. ✕ 15 min.
= 20 mi./hr. ✕ 0.25 hr.
= 5 mi.
B. distance = 6 mi./hr. ✕ 12 min.
= 6 mi./hr. ✕ 0.2 hr.
= 1.2 mi.
C. distance = 30 mi./hr. ✕ 2 min.
= 30 mi./hr. ✕ 0.0333 hr.
= 1 mi.
Time (minutes)
What was Dave’s average speed for the whole trip?
Average speed = total distance/total time
= (5 + 1.2 + 1) mi. / (15 + 12 + 2) min.
= 7.2 mi. / 29 min.
= 0.248 mi./min.
✕ 60 to get mi./min. → mi./hr.
= 14.9 mi./hr.
Distance (miles)
4 6 8 10 12 14
0
2
Average speed is the slope of the straight line
connecting the beginning and end points
of the interval.
0
4
8
12 16
20 24 28
Time (minutes)
Average speed = total distance/total time
= (5 + 1.2 + 1) mi. / (15 + 12 + 2) min.
= 7.2 mi. / 29 min.
= 0.248 mi./min.
= 14.9 mi./hr.
EXAMPLE: A distance vs. time plot for an object,
separated into intervals A,B,C,D,E,F
Distance
In which interval is the speed the highest?
E
C
B
D
F
B
In which interval is the object stopped completely?
E
In which interval has the object changed direction
and moved backwards?
A
C
Time
In which interval is the object’s speed not
constant?
D
10. From your experiences, give an example of a situation that can be explained using
the Law of Inertia. Please explain the context, and make clear how your example is
related to the Law.
The Law of Inertia (Newton’s First Law): In the absence of external forces, an object
moves in a straight line with constant speed.
One possible example:
A car going around a sharp turn needs to keep its speed
under control - because inertia tends to keep the car
traveling in a straight line at the same speed - unless an
external force is exerted by the road on to the car
This is why sharp turns on the
road (or turns on race tracks
are “banked”) - to exert a
stronger force on the car.
FORCE
Inertia - the tendency of a body/object to
maintain the same speed and direction
unless acted upon by an external force
When in your lab activities have you observed
objects maintaing a constant speed?
Rolling the blue ball down the hallway; timing the
steel ball travel fixed distances on the ramp
(Uniform Motion lab)
When in your lab activities have you observed
objects maintaing a constant direction?
Observing the steel ball when not in contact with a
plastic barrier (Steering a ball lab)
Does a non-moving object obey the Law of
Inertia?
Yes! You need to apply a force to get a non-moving
body moving, too.
WHAT YOU ARE EXPECTED TO KNOW:
- How to interpret varying behavior of data on a
distance vs. time plot
- How to solve problems involving speed,
distance and time
- How the Law of Inertia (Newton’s First Law)
affects a moving object
TODAY’S OUTCOMES:
SUN AND MOON
- Review and organize moon
observation activity✓
FORCE, MOTION AND ENERGY
- Review the interpretation of distancetime graphs; discuss inertia
- Study how forces interact between
objects
- Investigate how the height of an
inclined affects applied forces