Question

What is the period of a ball tied to a string of length 1.2 m making 4.5 revolutions every second?

Answer 1

I found `0.22` seconds.

Explanation:

The period is the amount of time needed to complete a revolution. Your ball makes `4.5` revolutions in `1` second so it will need:
`1/4.5=0.22` seconds for only one revolution.