1. Monday, March 13th
Entry Task Do YOU exert a gravitational force? Justify your answer.
Schedule:
12.1 notes & questions
Objective: I can explain that gravity is a force exerted by masses
Homework
12.1 notes & questions
Read pages carefully
Please have on desk:
Introduction to Chapter 12 (vocabulary)

2. What we learned before
Every action force has an equal and opposite reaction force
Newton’s laws are used to describe the motions of objects
Mass is the amount of matter an object contains.

3. Gravity is a force exerted by masses.
Gravity is a Universal Force because it acts between any things with mass.
Gravity requires 2 things with mass to be present.

4. Gravity is a force exerted by masses.
Greater Mass results in greater force
Greater distance results in smaller force.

5. Force of Gravity Depends On…
Mass of the objects
More mass  greater force of gravity
If mass is doubled, force of gravity doubles
Distance between the objects
More distance  less force of gravity
If distance is doubles, force of gravity is 1/4th

6. Earth exerts a downward (action) force on pencil
Pencil exerts an upward (reaction) force on Earth
Net force not strong enough to move earth (too much inertia), but can move the pencil

7. Acceleration due to Earth’s gravity is
Gravity accelerates objects
Acceleration due to Earth’s gravity is
9.8 m/s2 (1 G)
Free template from

8. W=mg
If an object is dropped on Earth it accelerates towards it because of the gravitational pull.
This acceleration is called g
g=9.8 m/s²
Newton’s 2nd law (from Chapter 11)
Formula F=ma
Substitute w for F
Substitute g for a
w=mg is the formula for calculating the weight of an object (it’s a force!) close to Earth’s surface

9. Gravity accelerates objects
A thrown object will hit the ground at the same time as a dropped object (If all other forces are absent)

10. Weight and Mass
MASS – The amount of matter in an object (Does not change based on surroundings)
WEIGHT – The amount of gravitational force acting on an objects (Does change based on surroundings)

11. Weight is a measure of the force of gravity
Because gravitational pull between you and the moon is weaker, you weigh less on the moon. REMEMBER…Weight and mass are different things

12. Tuesday, March 14th
Entry Task Gravity is pulling the moon toward the center of Earth. Why doesn’t it crash into Earth?
Schedule:
Relating Mass and Weight activity
Objective:
I will measure and graph the relationship between mass and weight.
Homework:
Complete the activity if not finished in class.
Please have on desk:
ISN open to 12.1 notes

13. Happy Pi Day

14. Wednesday, March 15th
Entry Task Calculate the weight of a 50 kg object on Earth. Write the formula, show your work with units and answer with units.
Schedule:
Gravity Review
Objective:
I can explain the relationship between mass, distance, and gravitational force
Homework:
Math problems if not finished in class
Please have on desk:
Relating mass and weight activity

15. Thursday, March 16th Entry Task
Why is this activity not safe on the moon, but is sort of safe on the earth?
Schedule:
Friction notes
Objective:
I can describe how friction affects motion.
Homework:
Finish the output page.
Please have on desk:
ISN, textbook, pencil

16. Friction Basics
Draw an example of Friction being necessary for motion.
Draw an example of Friction opposing motion

17. Friction Basics
What 3 things determine how much friction occurs between two surfaces?

18. Friction Basics
What happens to air resistance when surface area increases?
How about when speed increases?

19. Friction Basics
The types of surfaces of the objects; The speed of the object; The weight of the object
Surface Area increases = Friction Increases
Speed Increases = Friction Increases

20. As you read the Friction article,
Highlight important information
Circle Vocabulary words
Make annotations
At least 3 per page
Thought, feelings, questions, summarize

21. Friday, March 17th
Entry Task How can you decrease the friction between a dishcloth and a plate?
Schedule:
Science Friction
Bill Nye “Friction”
Objective: I can demonstrate my understanding of gravity and friction.
Homework:
No homework
Please have on your desk:
ISN open to mass and weight worksheet