Describe an experiment to estimate the speed of sound in air.

Estimation of speed of sound in air:

1. Suppose we choose two hills A and B about a kilometre apart.
2. A person at hill A fires a gun.
3. Another person at hill B starts a stop watch as he sees the flash of fire and stops it on hearing the sound.

He measures the time interval between the sight of flash and hearing the sound. Let it be t second.

Measure the distance between the hills A and B. Let it be d metre.

So speed of sound V = $\dfrac{\text{distance (d)}}{\text{time (t)}}$ = $\dfrac{\text{d}}{\text{t}}$ m s^-1.

Experimentally it is found that speed of sound in air is 330 m s^-1.