JEE Main 2023PhysicsMotion In One DimensionMediumMCQ

JEE Main 2023 — Motion In One Dimension Question with Solution

JEE Main 2023 (13 Apr Shift 1)

Question

Two trains A and B of length l and 4l are travelling into a tunnel of length L in parallel tracks from opposite directions with velocities 108 km h-1 and 72 km h-1, respectively. If train A take 35 s less time than train B to cross the tunnel then, length L of tunnel is:

(Given L=60 l)

Choose an option

Show full solutionCorrect option: C
Correct answer
C1800 m

Step-by-step explanation

The time taken for A

ΔtA=l+LVA

The time taken for B

ΔtB=4l+LVB

It is given that B takes more time than A. So,

⇒4l+L20-l+L30=35

⇒64l20-61l30=35

⇒l=35×600700=30 m

Therefore,

L=1800 m.

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About this question

This is a previous-year question from JEE Main 2023, covering the Motion In One Dimension 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.