JEE Main 2019PhysicsLaws of MotionMediumMCQ

JEE Main 2019 — Laws of Motion Question with Solution

JEE Main 2019 (10 Jan Shift 1)

Question

A block of mass m is kept on a platform which starts from rest with a constant acceleration g/2 upwards, as shown in the figure. Work done by normal reaction on block in time t is

Choose an option

Show full solutionCorrect option: D
Correct answer
D3 m g2t28

Step-by-step explanation


N-mg=mg2
N=3mg2
s=ut+12at2
=0+12g2t2
=g4 t 2
WN=3mg2×g4 t2
=3mg2t28=3mg2t28

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About this question

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