Question

A wheel on a watermill turns halfway every 4.0 s. What is the wheel's angular velocity?

A. 0.39 rad/s
B. 2.5 rad/s
C. 3.1 rad/s
D. 0.79 rad/s
E. 13 rad/s

Answer 1

A revolution equals 2*pi radians.
As the wheel rotates half every 4 seconds, then it means that it rotates half revolution.
Thus, the angular velocity of the wheel is given by:
w = (pi) / (4) = 0.79 rad / sec
answer
The wheel's angular velocity is 0.79 rad / sec