JEE Main 2016PhysicsLaws of MotionHardMCQ

JEE Main 2016 — Laws of Motion Question with Solution

JEE Main 2016 (03 Apr)

Question

A point particle of mass m, moves along the uniformly rough track PQR as shown in the figure. The coefficient of friction, between the particle and the rough track equals μ . The particle is released, from rest, from the point P and it comes to rest at a point R. The energies, lost by the ball, over the parts, PQ and QR, of the track, are equal to each other, and no energy is lost when particle changes direction from PQ to QR.
The values of the coefficient of friction μ and the distance x=QR , are respectively close to:

Choose an option

Show full solutionCorrect option: A
Correct answer
A0.29 and 3.5 m

Step-by-step explanation



tan⁡30o=hℓ

ℓ=h3=23 m

WPQ=-μmgℓ or WQR=-μmgx

μmgℓ=μmgx 

 x=ℓ≈3.5m

x=23 m

now according to work energy theorem

 Wall=∆K

mgh-μmgℓ-μmgx=0

h-μℓ-μx=0

2=μℓ+x⇒μ=2ℓ+x=243=123≈0.29

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About this question

This is a previous-year question from JEE Main 2016, covering the Laws of Motion 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.