Question

An observer is approaching with a speed v, towards a stationary source emitting sound waves of wavelength ${\lambda }_0$. The wavelength shift detected by the observer is (Take c= speed of sound)

Answer 1

Doppler Shift for a sound wave, when observer is moving towards a stationary source

$\lambda =\lambda \frac{(c+v)}{c}$ ${\lambda }^{\prime }=$ observed wavelength

${\lambda }^{\prime }-{\lambda }_0={\lambda }_0\left(\frac{c+v}{c}\right)-{\lambda }_0$ ${\lambda }_0=$ original wavelength

$c=$ speed of wave

$\Delta \lambda =\frac{{\lambda }_{0}v}{c}$ $v=$ speed of observer