Question bank/JEE Main/Physics

JEE MainPhysicsToughRelative motion

Rain is falling with constant and uniform velocity v at angle
37º vertical. An observer starts from rest and moves with uniform

acceleration
2m/s22m/s^{2} in horizontal direction (with the rain). After 6
sec. velocity of rain drop again appear at angle 37º from vertical.

Velocity of rain fall with respect to ground

is:
(tan37∘ =3/4)\left( tan37^{\circ} \right.\ = 3/4)

Show answer and solution
w.r.t observer
let final velocity of rain be v'

initial velocity of

rain
=3v5i^−4v5j^= \frac{3v}{5}\overset{\hat{}}{i} - \frac{4v}{5}\overset{\hat{}}{j}
[IMAGE] w.r.t observer.

acceleration of rain
=−2j^m/s2= - 2\overset{\hat{}}{j}m/s^{2}
final velocity of

rain
=−3v′5i^−4v′5j^= - \frac{3v^{'}}{5}\overset{\hat{}}{i} - \frac{4v^{'}}{5}\overset{\hat{}}{j}
in y- direction

Vy final =Vy initial V_{y\ final\ } = V_{y\ initial\ }
v′=vv^{'} = v

Source: Grass-G / P-05 Physics paper 10 October.docx

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