Answer:
Frequency=?,number of oscillation=57,time=3.
There are two ways to go about this....
You can other use this formula: frequency=number of oscillation/time.
which is 57/3=19Hz.
OR.
You can use this formula:Period is time/number of oscillation.. which is..
3/57=0.053.
and frequency is 1/T....The "T" stands for period.
So since frequency is 1/T then it will be 1/0.053=18.8~19Hz..
The answer is option B.
Thank you for the question I hope it helps you
