Review Grade 8 Unit 03: Force and Motion
- 1. What is Newton's First Law of Motion?
- 2. What is friction? How might it confuse people about Newton's First Law of Motion?
- 3. What is Newton's Second Law of Motion? Give your own example.
- 4. Select the correct choice: When balanced forces act on an object the objects motion will (change / not change). When unbalanced forces act on an object it will (change / not change).
- 5. What would be the acceleration of a 1,200 kg car that is exerting 1,590 N of forward force and experiencing 750 N of air resistance and friction?
- 6. Review the distance vs. time graph (pp. 166-167) and the speed vs. time graphs (pp. 172-173). For both, recognize the meaning of positive and negative slope, horizontal slope, and curved lines.
- 7. What is the difference between average speed and instantaneous speed?
- 8. What is the difference between speed and velocity?
- 9. How is it possible for an object to change its velocity but not its speed? Is it possible for an object to change its speed, but not its velocity? Why or why not?
- 10. What is it called when an object changes its velocity?
- 11. What is Newton's Third Law of Motion. Explain how it works in rowing a boat.