1. MOTION & FORCES CH. 10-11

2. d. motion: an object’s change in position relative to a reference point What is motion? How do you know the balloon moved?

3. Distance measures the actual path an object travels. Displacement measures the from start to finish in a straight line. Displacement

4. d. speed: distance traveled in a certain amount of time SI unit: meter/second (m/s) d. velocity: speed of an object in a certain direction examples? d. acceleration: any change in velocity (speed, direction, or both) SI unit: meter/second 2 (m/s 2 )

5. A car slows down to stop at a stop light. Which is which? A plane travels at 300 mph towards California. A cheetah runs 30 mph. A car turns left at an intersection. acceleration velocity speed acceleration

6. d. force: an action exerted on an object to change the object’s state of rest or motion has direction & magnitude What is another term for “state of rest or motion?” INERTIA! What is force?

7. FORCE S

9. d. friction: a force that opposes motion between two surfaces that are in contact What is the difference between static and kinetic friction? What is friction?

10. All objects in the universe attract each other through gravitational force. Gravity Sir Isaac Newton, 1642-1727

11. Gravity increases as mass increases.

12. Gravity decreases as distance increases.

13. An object at rest tends to remain at rest and an object in motion tends to stay in motion unless acted upon by an outside force. Newton’s 1st Law

14. The unbalanced force acting on an object equals the object’s mass times its acceleration. F = ma Newton’s 2nd Law

15. For every action, there is an equal & opposite reaction. Force always happens in pairs, even when there is no motion. Newton’s 3rd Law

16. When A swimmer pushes the water back, which way does she go? When you push down on the floor, which way do you go? Newton’s 3rd Law