A source of sound producing wavelength 50 cm is moving away from a stationay observer with `((1)/(5) )^(th)` speed of sound. Then what is the wavelength of sound received by the observer?

Options

A. 55 cm
B. 40 cm
C. 60 cm
D. 80 cm

Answer

C

Explanation

Here , wavelength of the source , `lambda` = 50 cm
Speed of the sound = v
speed of the source , `v_(s) = (1)/(5) ` V
As the source is moving away from the stationary observer, therefore the wavelength of sound received of sound received by the observer is
`lambda. = ((v + v_(s))/(v)) lambda = ((V + (1)/(5) v))/(v) lambda`
` = (6)/(5) lambda = (6)/(5) xx 50 ` cm = 60 cm .
correct choice is c.