# Action: Earth pulls moon.

```March 1 & 4
Homework
Due
Read & Study 12.1-12.4; do #1-7 p. 180
**Grade will be worth 5 points; ½ point per question and 1.5 points
given to a randomly selected problem the teacher will grade on
CORRECTNESS**
Tonight’s
HW
Read & Study 12.4-12.6; do #8-13 p. 180
**Grade will be worth 5 points; ½ point per question and 2
points given to a randomly selected problem the teacher will
Do Now
-
Last chance to claim your poster / fix it if it fell down? Any
left by next Wednesday will be thrown away!
Take a clicker
Action: Earth pulls moon.
What is the reaction?
What is stronger – action, reaction, or same?
Action: Earth pulls moon.
- What is the reaction?
- What is stronger – action,
reaction, or same?
Action: Earth pulls moon.
What is stronger – action, reaction, or
same?
1. Action(Earth pulls
moon)
2. Reaction (moon pulls
Earth)
3. Same!
0%
1
0%
2
0%
3
1. 1st Law
2. 2nd Law
3. 3rd Law
0%
1
0%
2
0%
3
• PHET Gravity and orbits
• Run the simulation and complete the Lab
Activity Sheet.
– This is due in 30 MINUTES for a grade – you
will (10 points based on completion)
– Then, we will have a graded, individual, 30
point POST LAB to assess this lab activity.
#1 –Why did Newton think there must
be a force acting on the moon?
1. It moved in a
straight line, not a
circle
2. It moved in a circle,
not a straight line
3. I had no clue how to
question
0%
1
0%
2
0%
3
#2 What did Newton conclude about the
force that pulls apples to the ground and
the force that holds the moon orbit?
1. They were different
forces
2. They were the same
force
3. I had no clue how to
0%
1
0%
2
0%
3
#3 If the moon falls, why doesn’t it get
closer to Earth?
1. It has a large tangential
speed, so it falls
around Earth and not
into it
2. It has a small tangential
speed, so it falls
around Earth and not
into it
3. I had no clue how to
0%
1
0%
2
0%
3
#4
• What is meant by tangential speed?
– Popcorn…
#5
• How did Newton check his hypothesis that
there is an attractive force between Earth and
moon?
– Popcorn…
#6
• What is required before a hypothesis can
become a theory?
– Popcorn…
#6
• What is required before a hypothesis can
become a theory?
– Popcorn…
#7 Since there is gravity between the
planets and the sun, why don’t the
planets crash into the sun?
1. They have small
tangential speeds, so
they fall around sun
and not into it
2. They have large
tangential speeds, so
they fall around sun
and not into it
3. I had no clue how to
0%
1
0%
2
0%
3
Choose the picture you think shows
the gravity forces on the Earth and
the Sun.
A.
B.
C.
D.
E.
0%
A.
0%
0%
B.
C.
0%
0%
D.
E.
How would these gravity forces
change if the Sun got more
massive?
A. Increase
B. Decrease
C. Stay the same
0%
A.
0%
B.
0%
C.
How would these gravity forces
change if the Earth was much
closer to the Sun?
A. Increase
B. Decrease
C. Stay the same
0%
A.
0%
B.
0%
C.
How would these gravity forces
change if the Earth got much less
massive?
A. Increase
B. Decrease
C. Stay the same
0%
A.
0%
B.
0%
C.
How would these gravity forces
change if the Earth and Sun were
moved farther apart?
A. Increase
B. Decrease
C. Stay the same
0%
A.
0%
B.
0%
C.
Choose the picture of how the Earth
would move if you “turned off” the
gravity forces.
A.
B.
C.
D.
E.
0%
A.
0%
0%
B.
C.
0%
0%
D.
E.
Changes to make to your post lab:
• Make sure #2 and 4 say massive
• Change the answer choices in #11 to
“enjoyable” rather than “useful”
• When you are done… Place in in
box upside down; RETURN
CLICKER IN ORDER; silently BEGIN