# Physics equations/06-Uniform Circular Motion and Gravitation/Q:friction/More practice

1

A merry-go-round has an angular frequency, $\omega$ , equal to 0.174 rad/sec. How many minutes does it take to complete 8.5 revolutions?

 a) 3.87 minutes. b) 4.45 minutes. c) 5.12 minutes. d) 5.88 minutes. e) 6.77 minutes.

2

A merry-go round has a period of 0.34 minutes. What is the centripetal force on a 89.6 kg person who is standing 2.25 meters from the center?

 a) 16.6 newtons. b) 19.1 newtons. c) 22 newtons. d) 25.3 newtons. e) 29.1 newtons.

3

A merry-go round has a period of 0.34 minutes. What is the minimum coefficient of static friction that would allow a 89.6 kg person to stand2.25 meters from the center, without grabbing something?

 a) 0.019 b) 0.022 c) 0.025 d) 0.029 e) 0.033

4

What is the gravitational acceleration on a plant that is 2.67 times more massive than Earth, and a radius that is 1.74 times greater than Earths?

 a) 5.7 m/s2 b) 6.5 m/s2 c) 7.5 m/s2 d) 8.6 m/s2 e) 9.9 m/s2

5

What is the gravitational acceleration on a plant that is 1.95 times more dense than Earth, and a radius that is 2.12 times greater than Earth's?

 a) 40.5 m/s2 b) 46.6 m/s2 c) 53.6 m/s2 d) 61.6 m/s2 e) 70.9 m/s2