# Impulse, momentum conservation, potential energy

1. Define the term impulse.

2. Using the principle of momentum conservation, explain what happens when a moving billiard ball collides with a stationary ball (cue ball hitting the eight ball).

3. Explain the difference between energy and power and how they are related to work. Give examples of each).

4. A 1000 kilogram care is lifted 1 meter.

a. What is the potential energy with respect to the floor?

b. If the car is lifted 2 meters high, what is the new value of potential energy with respect to the floor?

c. Explain the following: Potential energy of an object varies linearly with position (height).

5. As you catch a fast-moving fastball, why is it wise to move your hand in the direction of the ball's motion? Explain in terms of work and energy.

6. If a sprinter running at a speed of 10 meters per second could convert his/her kinetic energy into upward motion, how high could he/she jump?

7. What various forms of energy are present as you shoot a bow and arrow?

8. a. If you push a lawn mower across a yard in 10 seconds, how does the work done compare with pushing it across the same yard in 20 seconds? Explain why.

b. How does the power for 10 seconds compare to the power for 20 seconds?

9. How many kilometers per liter will a car obtain if its engine is 25 percent efficient and it encounters and average force of 1000 Newtons? Assume the energy content of gasoline is 40,000,000 joules per liter (J/L).

#### Solution Preview

Please find the solutions attached.

1. Define the term impulse.

Solution:

Impulse is defined as the change in momentum.

2. Using the principle of momentum conservation, explain what happens when a moving billiard ball collides with a stationary ball (cue ball hitting the eight ball).

Solution:

When moving billiard ball hits the stationary ball straight then the moving ball will stop. It will transfer its momentum to the stationary ball and stationary ball will start moving at the same speed as the moving ball due to principle of momentum conservation.

3. Explain the difference between energy and power and how they are related to work.

Solution:

Energy can be defined as the capability to do work. Power is the rate of work or energy. Work is the change in energy while power = Work/time.

4. A 1000 kilogram care is ...

#### Solution Summary

Impulse, momentum conservation, potential energy and forms of energy is examined.