Question

a ruler vibrates 70 times in 20 seconds. what is the frequency of a vibration​

Answer 1

Answer:

if the object vibrates 30 times in 2 min, then it vibrates 15 times in 1 min.

Then we divide 15 by 60(seconds), which gives us 0.25, and this is our frequency.

Obs: We divide 15 by 60 because frequency means how many periods in one second, and 1 minute have 60 seconds, and then, that’s why we divide by 60.

Similarly, if you want to know the period, you divide 1/frequency , because frequency is the inverse of period, which gives us 4, and this means that 1 vibration takes 4 seconds.