Question

Rain drops appears to a man falling vertically but when he starts moving with a velocity of 10m/sc horizontally when the rain drops appears to hit him an angle of 60° from horizontal .Then what is the actual velocity if rain

Answer 1

Explanation:

Let the rain velocity components are r

h

(horizontal) and r

v

(vertical).

v

= r

v

i

^

+r

h

j

^

Then

r

h

r

v

=

3

when he is travelling at 5 km/hr, the relative velocity of rain w.r.t. man will be

v

rel

= r

v

i

^

+(r

h

+5)

j

^

(as the man will have to go backwards to decrease angle)

and

r

h

+5

r

v

=

3

1

These 2 equations give r

v

= 5

3

/2 and r

h

= 5/2. Hence total velocity =5