Answer
$ 7.14 \ s $
Work Step by Step
We first convert rpm to radians per second. We must find the difference in the two frequencies in order to solve. Thus, we find:
$ f_1 = \frac{\omega}{2\pi}=\frac{103.09}{2\pi}=16.41\ Hz$
$ f_2 = \frac{\omega}{2\pi}=\frac{103.934}{2\pi}=16.55\ Hz$
Thus, the difference is .14 Hz. This means:
$ T = \frac{1}{.14} = 7.14 \ s $
