posted by phincter .
A person is riding a bicycle, and its wheels have an angular velocity of 28.9 rad/s. Then, the brakes are applied and the bike is brought to a uniform stop. During braking, the angular displacement of each wheel is 13.6 revolutions. (a) How much time does it take for the bike to come to rest? (b) What is the anguar acceleration (in rad/s2) of each wheel?
a. 28.9rad/s * 1rev/6.28rad = 4.60 rev/s.
t = (13.6/4.60) * 1s = 3.0 s.
b. V = Vo + at = 0 When @ rest.
28.9 + a*3 = 0
3a = -28.9
a = -9.63 rad/s^2.