A man sitting in a bus travelling in a direction from west to east with a speed of 40 km/h observes that the raindrops are falling vertically down. To the another man standing on ground the rain will appear 

A man is sitting in a bus and travelling from west to east, and the rain drops are appeared falling vertically down.

${\text{v}}_{\text{m}}=$Velocity of man

${\text{v}}_{\text{r}}=$Actual velocity of rain which is falling at an angle $\theta$ with vertical

 ${\text{v}}_{\text{rm}}=$Velocity of rain w.r.t to moving man 

If the another man observe the rain then he will find that actually rain falls with velocity at an angle going from west to east.