Question

a man is walking due east at 5kmph and rain appears to fall vetically downwards at 12kmph for him. Then true velocity of rain in KMPH is

Answer 1

Picture is below
Hope u understood

Answer 2

Answer:

VRain,Person =VRain−VPerson=−5j^ (vertically down)

Thus, VRain −(−5i^)=−5j^ (west means −5i^)

or, VRain=−5i^−5j^

​Thus, magnitude = 5$\sqrt{2}$ km/hr, direction is in 3rd quadrant, i.e. clockwise to vertical at an angle of tan−1(5/5)=45o to vertical

Explanation: