JEE Main 2014PhysicsMotion In One DimensionMediumMCQ

JEE Main 2014 — Motion In One Dimension Question with Solution

JEE Main 2014 (19 Apr Online)

Question

A bullet loses 1nth of its velocity passing through one plank. Considering uniform retardation, the number of such planks that are required to stop the bullet can be:

Choose an option

Show full solutionCorrect option: C
Correct answer
Cn22n-1

Step-by-step explanation

 
Let t be the thickness of the plank

υ01-1n2=υ02-2at

∴ 2at=υ02-υ021-1n2

If m number of planks are required to stop a bullet, then

0=υ02-2atm

∴ m=υ022at

=υ02υ021-1-1n2

=n2n2-n-12=n22n-1

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Motion In One Dimension chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.

Solve interactively →

About this question

This is a previous-year question from JEE Main 2014, 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.