Question

A pendulum oscilates 40 times in 4 seconds . calculate its timeperiod and frequency .can we hear the sound produces by the oscillation of this pendulum give reson to our answer

Answer 1

time period is the time taken for 1oscillation
so .here in 4sec no of ossilations are 40so
for 1oscillatons time will be 4/40sec=1/10sec
time period =1/10sec
Freq=1/time period
so.freq=1/1/10=10hz
sound can only be heard by our eye if it's in certain range of Freq otherwise not