A man walks in rain with a velocity of 5 kph. The rain drops strike at him at an angle of `45^(@)` with the horizontal. The downward velocity of the rain drops will be :

Options

A. `5" kmh"^(-1)`
B. `4" kmh"^(-1)`
C. `3" kmh"^(-1)`
D. `1" kmh"^(-1)`

Answer

A

Explanation

`overset rarr V _(r)= V_(2) j`
`overset rarr V_(m)=5 overset ^i`
`overset rarr V_(r)-overset rarr V_(m)=(-5) overset ^i+ V_(y)overset ^ j`
`tan theta = 1 = (V_(y))/(5)`
So `V_(y)= 5 "km/h"`