angular velocity

Question

A femur which is 0.5 m long (meaning the end of the femur is 0.5 m from the axis of rotation) moves through an angle of 0.52 rad in 0.5s.

a) what is the average angular velocity of the end of the femur?

b) what is the average angular velocity of the greater trochanter, which is 0.004 m from the axis of rotation?

c) what is the average linear/tangential velocity of the end of femur?

d) what is the average linear/tangential velocity of the greater trochanter?

Answer 1

a) w (angular velocity) = theta (angle) / T (time)

w = 0.52 * 0.5 = 0.26 rad/s

b) Same as above as neither the angle nor time changes with the radius:

w (angular velocity) = theta (angle) / T (time)

w = 0.52 * 0.5 = 0.26 rad/s

c) v (linear velocity) = r (radius) * w (angular velocity)

v = 0.5 * 0.26 = 0.13 m-rad/s

d) v (linear velocity) = r (radius) * w (angular velocity)

v = 0.004 * 0.26 = 0.00104 m-rad/s