A sound wave is produced fron a source ans an echo is hea...
A sound wave is produced fron a source ans an echo is heard t seconds afterwards. If d is the distance of the reflecting surface from the source, v the speed, p the wavelength and T the period of the wave, then
d = 2tλ
d = λt2T
d = 2Tλt
d = λT2t
Correct answer is B
V = 2dt
fλ=2dt=λT=2dt