Figure below shows boat and river with their respective speeds. S is a source, attached to the boat, that emits sound of wavelength 14.45 mm at a speed of 1445 m/s w.r.t water. A receiver is kept downstream at rest w.r.t. ground, inside water. The frequency detected by the receiver is:-

Options

A. 100695.9 Hz
B. 100556.7 Hz
C. 101391.2 Hz
D. 100696.9 Hz

Answer

A

Explanation

`v = f lambda`
`f=10^(5)` Hz
`rArr` Velocity of sound w.r.t. to ground
=1447 m/s
`rArr f_(spp) = 1447/(1447-10) xx 10^(5)`
= 100695.9 Hz