JEE Main 2019PhysicsCenter of Mass Momentum and CollisionHardMCQ

JEE Main 2019 — Center of Mass Momentum and Collision Question with Solution

JEE Main 2019 (10 Apr Shift 1)

Question

Two particles of masses M and 2M are moving with speeds of 10 m s-1 and 5 m s-1, as shown in the figure. They collide at the origin and after that they move along the indicated directions with speeds v1  and  v2, respectively. The values of v1 and  v2 are, nearly

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Show full solutionCorrect option: C
Correct answer
C13.02 m s-1 and 19.7 m s-1

Step-by-step explanation


From conservation of linear momentum,
Along x-axis:

10Mcos300+52Mcos450=Mv1cos300+2Mv2cos450
10 M 32+ 10M12=M32 v1+2Mv212
32 v1+2v2=5(3+2) … (1)
Along y-axis:
-10M12+10M12=Mv112-2Mv212
 v12-2v2=5(2-1) … (2)
From equations (1) and (2)
v132+12=53+2+5(2-1)
v1=13.02 m/s
v2=53+52-13.02×322
=19.72 m s-1

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About this question

This is a previous-year question from JEE Main 2019, 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.