       Here is your chance to apply what you've learned in this chapter. We first studied projectile motion. We learned that all falling objects follows the same path. Then we analyzed periodic motion, which repeats itself. The force that causes an object to make a circular path is called the centripetal force. You can use the formula sheet if you need some help. Support easyphysics.net by visiting our advertisers' websites. You should have a piece of paper and a pencil with you.

## Chapter 6 Quiz

1. A baseball was thrown from 1 m hill. Assume that the ball had an initial velocity of 70 km/h (19.44 m/s) at 40 degrees.

a. What was the initial velocity on x direction?

m/s

b. What was the initial velocity on y direction?

m/s

c. How long will it take for the ball to land on the ground?

s

d. How far will the ball travel?

m

2. Pete throws a tennis ball horizontally from the top of the 50 m building. Assume that the ball landed 100 m away from the building.

a. How long did it take for the ball to reach the ground?

s

b. What was the initial velocity on x direction?

m/s

c. What was the velocity of the ball when it hit the ground?

m/s

3. Michael is competing in the long jump. Assume that his total velocity (velocity of x and y directions combined) right before he jumped was 6.5 m/s.

a. If he jumped at an angle of 35 degrees, what would his vertical velocity be?

m/s

b. How long will he stay in the air then?

s

4. A 1300 kg car takes 35 s to travel around a circular road that has a radius of 40 m.

a. What is the velocity of the car?

m/s

b. What is the acceleration of the car?

m/s2

c. How big should the force of friction be to maintain this acceleration?

N

d. How big should the coefficient of the force of friction be?

5. A coin is placed on a stereo record, which takes 3 seconds to make a complete revolution. Assume that the coin has a velocity of 5 m/s.

a. What is the acceleration of the coin?

m/s2

b. What is the distance from the center of the stereo record to the coin?

cm

c. How big is the coefficient of the force of friction between the stereo and the coin?