What is the angular speed of a car wheel of diameter 0.400m when the speed of the car is 108km/h?

A) 75 rad/s      B) 150 rad/s      C) 270 rad/s      D) 540 rad/s       Identify equation as w=v/r      Diameter = 0.4m  Radius  = half the diameter = 0.2m       Velocity needs to be in m/s so 108km/h = 108000m/h = 30m/s (divide by 60 twice).       Angular velocity = v/r = 30/0.2 = 150 therefore B is the answer.