Question

If a shower of rain appears to be falling vertically downwards with a velocity of 12 kmph to a person
walking towards west with a speed of 5 kmph. Then velocity of the rain.
a) 17 kmph
b) 15 kmph
c) 13 kmph
d) 11 kmph
​

Answer 1

Answer is 13 kmph by Pythagoras Theorem

Answer 2

ANSWER:

The resultant velocity is 13 kmph

EXPLANATION:

    A person is walking and feels that the rain is falling vertically on him, it can be said that the rain is travelling in the same direction as the persons motion is. Hence using the velocity as vector unit; the rain falling vertically downward with no horizontal movement means that the velocity of both the person and the rain droplets is around 5 km per hour.  

Therefore the resultant velocity of the vertical and horizontal motion is

The resultant velocity is $V_{R}=\sqrt{12^{2}+5^{2}}=\sqrt{169}$

$V_{R}=13$