Rotational Motion Question 64

Question: A particle of mass m moves in the XY plane with a velocity v along the straight line AB. if the angular momentum of the particle with respect to origin O is LA when it is at A and LB when it is at B, then:

[AIPMT (S) 2007]

Options:

A) LA>LB

B) LA=LB

C) the relationship between LA and LB depends upon the slope of the line AB

D) LA<LB

Show Answer

Answer:

Correct Answer: B

Solution:

  • From the definition of angular momentum,

    L=r×p=rmvsinϕ(k)

    Therefore, the magnitude of L is

    L=mvrsinϕ=mvd

    where d=rsinϕ is the distance of closest approach of the particle to the origin.

    As d is same for both the particles, hence LA=LB .



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Dual Pane