1. 8th Grade Physics Changing Motion Unit

2. Force
A push or a pull.
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3. Magnitude The strength of an object or event.
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4. Balanced Force
30N
30N
The net force on an object is zero and the object’s motion does not change.
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5. Unbalanced Force
50N
20N
The net force of an object does not equal zero which results in a change in the motion of the object.
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6. Net Force
The sum of all the forces acting on an object. (same direction=add, opposite directions= subtract)
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7. What is Motion?
Motion: A change in position of an object compared to a reference point
Motion involves all of the following:

8. Forces affect Motion: They can make objects start moving.
They can make objects move faster.
They can make objects move slower.
They can make objects stop moving.
They can make objects change direction.
They can make objects change shape.

9. Speed The distance traveled by an object in a given amount of time.
Speed= Distance
time
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10. Velocity
Speed + Direction

11. Acceleration
The rate at which an object’s speed and/or directions changes over time.
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12. Friction
The force between objects that affects how easily they move past each other.
Image: Definition: Access Science glossary, page 315.

13. What is Friction?
What are some ways athletes uses friction?

14. Gravity A force that pulls objects together.
Gravity caused the apple to fall on Sir Isaac Newton’s head.
Image from: Definition adapted from: Access Science glossary, page 316.

15. Calculate To figure out by computation.
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16. Potential Energy Energy at rest or stored energy.
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17. Kinetic Energy Energy in motion.
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