Answer
a) $T=5\times10^{-5}s$
b) $f=2\times10^4Hz$
c) $\omega=1.26\times10^5rad/s$
Work Step by Step
a) The period of the rotational motion, or the time the fan blades make one revolution is $$T=\frac{50\times10^{-3}s}{10^3rev}=5\times10^{-5}s$$
b) The frequency of the motion is $$f=\frac{1}{T}=2\times10^4Hz$$
c) The angular frequency of the blades is $$\omega=\frac{2\pi }{T}=1.26\times10^5rad/s$$
