Chapter 4: Momentum and Energy - Review Questions

1. Which has greater momentum, a heavy truck at rest or a moving skateboard? Explain. 
2. Why might a drink glass survive a fall onto a carpeted floor but not on a concrete floor? 
3. How can a huge ship have an enormous momentum when it moves relatively slowly? 
4. When can a 1000 kg car and a 2000 kg truck have the same momentum? 
5. What are two ways in which the impulse exerted on something can be increased? 
6. How does impulse differ from force? 
7. For the same force, which cannon imparts the greater speed to a cannonball - a long-barreled cannon or a short-barreled one? Explain. 
8. Does a moving object possess impulse? Does a moving object possess momentum? Explain. 
9. What does it mean to say that a quantity is conserved - for instance, conservation of momentum. 
10. What do we call the quantity force x distance, and what quantity does it change? 
11. How much work is needed to lift an object that weighs 500-N to a height of 2-m? How much work is needed to lift the same object twice as high? 
12. How many watts of power are are expended when a force of 6-N moves a book 2-m in a time interval of 3-s? How much power is needed to doe the same job in 1-s? 
13. Two cars, one twice as heavy as the other, are lifted to the same elevation in a service station. How do their potential energies compare? 
14. How much work is done in lifting a 100-N object a vertical distance of 2-m? How much work is done in pushing the same object up a 4-m long ramp? (The force needed here is only 50-N, which is the reason inclines are used.) What is the difference in the object’s PE in each case? 
15. When a car travels at 50 km/h, it has KE. How much more KE does it have at 100 km/h? 
16. What is the evidence for saying whether or not work is done on an object? 
17. Cite the law of energy conservation. 
18. Can an object possess energy? Can an object possess work? 
19. Can something have energy without having momentum? Explain. Can something have momentum without having energy? Defend your answer. 
20. Consider a pendulum swinging to-and-fro. At what point is the KE of the pendulum bob at a maximum? At what point is the PE at a maximum? When its KE is half its maximum value, how much PE does it have?