Answer: frequency f = 2000 1/s (Hz)
Explanation: period T means time for one cycle and frequency f tells how many cycles there are in seconds. Unit of frequency is 1/s= Hz. Period T = 1/f and frequency f= 1/T.
E.g is T= 0.01 s then f= 1/ (0.01 s) = 100 Hz. And I'd frequency is 20 Hz,
T= 1/(20 Hz)= 0.05 s. So, if T = 0.005 s, f= 1/T
