A car sounding its horn at `480Hz` moves towards a high wall at a speed of `20ms^(-1)`, the frequency of the reflected sound heard by the man sitting in the car will be nearest to , (speed of sound `=330m//s)`

Options

A. `480Hz`
B. `510Hz`
C. `540Hz`
D. `570Hz`

Answer

C

Explanation

Here, `upsilon_(s)=+20m//s, upsilon_(L)=-20m//s`
`v=480Hz, upsilon=330m//s`
As, `v^(')=(upsilon-upsilon_(L))/(upsilon-upsilon _(s))v=(330-(-20))/(330-20)xx480=542Hz`
`=~~540Hz`