JEE Main 2020PhysicsLaws of MotionHardNumerical

JEE Main 2020 — Laws of Motion Question with Solution

JEE Main 2020 (03 Sep Shift 2)

Question

A block starts moving up an inclined plane of inclination 30° with an initial velocity of v0. It comes back to its initial position with velocity v02. The value of the coefficient of kinetic friction between the block and the inclined plane is close to 11000, The nearest integer to I is :

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Show full solutionCorrect answer: 346
Correct answer
346

Step-by-step explanation

A to B

a1=g sin 30°+μg cos 30°

=g2+μg32 ; g=10 m s2

v02-2a1s=0

s=v02a1    .....(i)

B to A

a2=g2-μ32g

V022=2a2s

s=V024a2  .....(ii)

From equation (i) and (ii)

V02a1=V024a2

⇒   a1=4a2

⇒   5+53μ=45-53μ

⇒   5+53μ ⇒25 3μ=15  ⇒  μ=35=0.346=3461000

So, 11000=3461000 

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About this question

This is a previous-year question from JEE Main 2020, 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.