JEE Main 2021PhysicsCenter of Mass Momentum and CollisionMediumNumerical

JEE Main 2021 — Center of Mass Momentum and Collision Question with Solution

JEE Main 2021 (24 Feb Shift 1)

Question

A ball with a speed of 9 m s-1 collides with another identical ball at rest. After the collision, the direction of each ball makes an angle of 30° with the original direction. If the ratio of velocities of the balls after the collision is x:y, then what is the value of x?

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Correct answer
1

Step-by-step explanation

From conservation of momentum along y-axis.

P→iy=P→fy

0+0=mv1sin30°j^+mv2sin30°-j^

mv2sin30°=mv1sin30°

v2=v1 or v1v2=1

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About this question

This is a previous-year question from JEE Main 2021, covering the Center of Mass Momentum and Collision chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.