SCI-113 Chapter 3 Homework Assignment Exercises

1. When a golf ball is hit with a force, why does contact with the golf club for a longer time cause a larger velocity than contact for a shorter time?

2. For question 2 above, what is this force for a given time called?

3. What has greater momentum, a truck at rest or a flying bird?

4. A railroad car (car1) moving at a constant speed hits another railroad car (car2) that is at rest in a perfectly elastic collision. After the collision, car1 is at rest. What is the speed of car2 after the collision compared to car1 before the collision?

5. For question 4 above, if the two cars couple together (remain connected together) perfectly inelastically (meaning no heat and they don't deform) after the collision, how does the speed of the two coupled together compare to the speed of car1 before the collision?

6. If all the work done on an object only changes the velocity of the object, what is the effect on its kinetic energy?

7. Provide an example of a force being applied to an object without any work being done.

8. What is the amount of work done if a Force of 2.4N is applied to an block to move it 3.0m on the floor?

9. How much power (in Watts) is needed to lift a rock in 2 seconds to give it 200 Joules of potential energy?

10. If a 10kg ball has 500J of potential energy (PE) at the top of a hill, and it rolls to the bottom of the hill with no frictional losses, what is the balls speed at the bottom of the hill (Hint: kinetic energy is mv²).