Rain appears to fall vertically to a man walking at `3kmh^(-1)` but if he changes his speed to double, the rain appears to fall at `45^(@)`. The real velocity of rain is

Options

A. `3sqrt(2)kmh^(-1),45^(@)`
B. `2sqrt(3)kmh^(-1),45^(@)`
C. `3sqrt(2)kmh^(-1),30^(@)`
D. `2sqrt(3)kmh^(-1),60^(@)`

Answer

A

Explanation

`sin theta=(v_(m))/(v_(r))`
`(v_(m))/(v_(r))=sin 45 =1/(sqrt(2))`
`v_(r)=(v_(m))/(sin 45)=3sqrt(2)kmh^(-1)`