Question

a) Find the angular velocity of a 40 cm radius wheel that is moving at 20 m/s.
b) How many times will this wheel rotate in 5 seconds?

Answer 1

r = 0.40 meters

angular velocity = omega = w

linear velocity = v

v = w r = 20 m/s

so 20 = w * 0.40

w = 200/4 = 50 radians/second

so for part b
50 radians/s * 5 s * 1rev/2pi rad
=125/pi revs

Answer 2

r is radius so it cant be 20 m/s