Question

The given graph shows the displacement versus time relation for a disturbance travelling with velocity of 1200ms-1. calculate the frequency of the disturbance.
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Answer 1

Given that,

Velocity = 1200 m/s

We know that,

Time Period is the number of seconds per waveform or the number of seconds per oscillation.  It is clear that frequency and period are reciprocals.

$T=\dfrac{1}{f}$

According to diagram,

The time period for one wave is 4 ms.

$T=4\times10^{-3}\ sec$

We need to calculate the frequency of the disturbance

Using formula of time period

$T=\dfrac{1}{f}$

$f=\dfrac{1}{T}$  

Where, T = time period

Put the value into the formula

$f=\dfrac{1}{4\times10^{-3}}$

$f=250\ Hz$

Hence, The frequency of the disturbance is 250 Hz.