1. Gravity-Mass and Distance
Notes
SPI
Gravity-Mass and Distance
Science
Learning Intention: Explain how mass and distance effect gravity.
Purpose: to understand why massive objects have more gravity than objects with less mass and the role of distance.
Success Criteria
I will show that I understand this topic by earning a 90 or
higher on the quiz.
I Can Statement
By the end of this unit I will be able to say...
...I can explain how gravity is effected by mass and distance.

2. Law of Universal Gravitation
Gravity
is a “mysterious” attractive force found everywhere in the universe that pulls particles of matter together
Key Concept: Gravity is a pulling force (not a pushing force)
F.Y.I. -Isaac Newton is credited with defining this law...
…states that gravity is everywhere in our universe, and that this attractive force changes based on mass and distance.
Reminder: Mass is the amount of matter in an object
Summary: Every particle of matter (atom/element) is attracted to every other particle of matter (atom/element).
Law of Universal Gravitation

3. Bowling Ball & Baseball (Imagine these objects are floating in space)
Mass Effects Gravity
Objects with more mass have more gravity than less massive objects.
Look below: (bowling ball and a baseball)
both are made of matter, so both objects have gravity.
Yet the ball with more mass (bowling ball) has more gravity.
Therefore its pull is stronger (view animation)
Bowling Ball & Baseball
(Imagine these objects are floating in space)

4. The example of a bowling ball and a baseball is similar
to the gravitational effect with a planet and a moon.
Earth and the Moon
Earth has more mass than the Moon.
Therefore, Earth also has more gravity then the Moon.

5. (Imagine these objects are floating in space)
Mass Effects Gravity
Look below: (baseball and a golf ball) both objects are made of matter, so both objects have gravity.
So both objects are being pulled towards each other.
Yet the ball with more mass (baseball) has more gravity.
Therefore its pull is stronger (view animation)
This is similar to the gravity between a moon and a asteroid
Baseball & Golf Ball
(Imagine these objects are floating in space)

6. Notice the size of the Sun contrasted with the planets
The Sun is bigger because it has more matter (mass)
Because it has more mass, it likewise has more gravity
The sun has more gravity than all other planets combined!
Note: The planets are not
actually this close to the Sun

7. Therefore, Jupiter has more gravity than Earth.
Jupiter has more mass than Earth.
Therefore, Jupiter has more gravity than Earth.
Earth
The Moon
The Earth has more mass than the Moon.
Therefore, Earth has more gravity than the Moon.

8. Distance Effects Gravity
gravity increases when objects are closer together.
gravity decreases when objects are farther apart.
Diagram 01: the two soccer balls are 5m apart (floating in space).
Diagram 02: the two soccer balls are 10m apart (floating in space.
Gravitation attraction is greatest when they are closer together.
5 meters
Diagram 01
10 meters
Diagram 02

9. Gravity-Mass and Distance Distance Affects Gravity
The Sun
SPI
Gravity-Mass and Distance
Earth
Moon
Distance Affects Gravity
The Sun has much more gravity than the Moon.
Yet the Moon is closer to Earth than the Sun.
So the Moon’s gravitation pull on Earth’s oceans (tides) is greater than the Sun’s gravitation pull.

10. Gravity and the Theory of Relativity
Enrichment:
Gravity and the Theory of Relativity
F.Y.I. -Einstein theorized that mass warps (bends/curves) space and this warping explains the force we call gravity.
Watch these Youtube videos:
Write down 3 things that catch your attention. Be ready to share.
Link: Curvature of Space-Time (34 sec)
Link: How Gravity Really Works (1 min 45 sec)

11. Gravity-Mass and Distance
Quick Review
SPI
Gravity-Mass and Distance
Science
1) What is the name of the law about gravity? The law of…
A) …Conservation of Mass or B) …Universal Gravitation
2) All matter in the universe attracts other matter by?
A) A “pushing force” or B) A “pulling force”
3) The strength of gravity depends on the ______ of the objects
A) Mass or B) Shape
4) Effect of gravity depends on the _____ between the objects.
A) Energy or B) Distance
5) What did Einstein say about mass and gravity?
A) That mass warps space or B) Mass and gravity are the same

12. Gravity-Mass and Distance
SPI
Gravity-Mass and Distance
Questions
Science
Mass Effects Gravity

13. Gravity-Mass and Distance Distance Effects Gravity
SPI
Gravity-Mass and Distance
Questions
Science
Distance Effects Gravity

14. Gravity-Mass and Distance Distance Effects Gravity
SPI
Gravity-Mass and Distance
Questions
Science
Distance Effects Gravity

15. Gravity-Mass and Distance
SPI
Gravity-Mass and Distance
Questions
Science
Mass Effects Gravity

16. Gravity-Mass and Distance Distance Effects Gravity
SPI
Gravity-Mass and Distance
Questions
Science
Distance Effects Gravity