PRACTICE QUIZ 7C

Answer the following questions completely and clearly.

1. Thanks to the Earth's rotation, you move with uniform circular motion. What supplies the centripetal force that keeps you moving in this circle?

 

2. What supplies the centripetal force necessary to keep a car moving safely around a curve without "flying out of control?"

 

3. Does the Earth revolve or rotate on its axis?

  

Solve the following. Show all work and circle your answer.

 

4. A child on a merry-go-round is moving with a speed of 1.35 m/s when 1.20 meters from the center of the merry-go-round. Calculate...

a. the centripetal acceleration of the child

 

 

 

b. the net centripetal force exerted on the child (mass = 25.0 kg)

 

 

 

 

5. Calculate the centripetal acceleration of the Earth in its orbit around the Sun and the centripetal force exerted on the Earth. What exerts this force on the Earth. Assume that the Earth's orbit is a circle of radius 1.50 x 10¹¹ m and that the Earth's mass is 5.97 x 10²⁴ kg. (Hint: How many seconds does the Earth take for one complete revolution?)

 

 

 

 

6. Ellen is riding her favorite roller coaster, the Screamer, through a loop with a bottom radius of 15.0 meters and a top radius of 6.4 meters. Her speed at the top is 10.0 m/s and her speed at the bottom is 18.0 m/s. What is the normal force applied to Ellen at the top and bottom of the loop if her mass is 60.0 kg?