Two sound waves of wavelengths 40 cm and 40.5 cm produce 10 beats per second. What will be the speed of sound in air ?

Options

A. 324 m/s
B. 340 m/s
C. 330 m/s
D. 360 m/s

Answer

A

Explanation

`n_(1) - n_(2) = n`
`(v)/(lamda_(1)) - (v)/(lamda_(2)) = 10`
`v[(1)/(40) - (1)/(40.5)] xx 10^(2) = 10`
`v = (40 xx 40.5 xx 10)/(0.5 xx 10^(2)) = (4 xx 405)/(5)`
`v = 4 xx 81 = 324 m//s`