1. Miss Sauer’s 7th Grade Science
Gravity
Miss Sauer’s 7th Grade Science

2. Do Now: What is a force? What is inertia? What is matter?
A push or pull.
A tendency of all objects to resist any change in motion.
Anything that takes up space and has mass.
Defying Gravity!:

3. What is Gravity?
Gravity: force of natural attraction between all objects in the universe.
Gravity’s formula: f = m * a
f = force (or weight)
m = mass
a = acceleration

4. Gravity
All objects in the universe are attracted to one another because of the force of gravity between them. This idea is now known as Newton’s law of gravity, or universal gravitation.

5. Gravity
No matter where on the Earth you stand, an object falls in the direction of the Earth’s center when you drop it.

6.
Gravity & Mass
The amount of gravitational force between two objects depends on the mass of each object.
The greater an object’s mass, the greater the object’s gravitational pull.

7. Gravity
Because the Earth’s mass is so large, all items on Earth are held in place by Earth’s gravitational pull.

8. Gravity & Distance
The force of gravity between two objects decreases as the distance between them increases.
What type of relationship is that?
The force of gravity decreases by an amount equal to one divided by the distance (d) squared, or 1/d2.
Indirect Relationship

9. Factors Affecting Gravitational Pull:
Mass
Distance

10. Factors Affecting Gravitational Pull: Mass
More Massive Less Massive
Stronger Pull
Weaker Pull

11. Factors Affecting Gravitational Pull: Distance
Closer Further
Stronger Pull
Weaker Pull

12. What is mass????
Mass is the amount of matter in an object.

13. What is weight????
The weight of an object is a measure of the gravitational pull acting on the object’s mass.

15. Mass vs. Weight An object’s MASS NEVER CHANGES, but WEIGHT CAN.
The weight of an object is a measure of the gravitational pull acting on the object’s mass. An object’s weight depends on its mass, as well as its location.

17. Mass vs. Weight Force of Gravity on Earth = 1.00 N
For example, you would weigh less on Mars than you do on Earth because the pull of gravity on Mars is weaker than the pull of gravity on Earth.
Force of Gravity on Earth = 1.00 N
Force of Gravity on Mars = 0.38 N

18. Gravity in Space
Astronauts can float in the air because the decreased gravity means decreased weight.

19. What is Inertia????
Inertia is the tendency of all objects to resist any change in motion.
The amount of mass determines the amount of inertia an object has.
Remember: When a car stops short, your body continues to move forward because you were travelling forward & your body wants to resist the change in motion.

20. Closure Questions
Definitions of force, matter, mass, weight, inertia, & gravity.
What scientific law explains why objects fall?
In what direction do objects fall on Earth?
How does mass impact gravitational pull?
How does distance impact gravitational pull?
What makes Earth’s gravitational pull so strong?
Does mass or weight depend on your location?