menu search
brightness_auto
Feel free to answer or ask any questions.
If you are new here please see how to use or FAQ.
more_vert
A particle of mass m with an initial velocity $u\hat{\text{i}}$ collides perfectly elastically with a mass 3 m at rest. It moves with a velocity $v\hat{\text{j}}$ after collision, then, $v$ is given by

(1) $v=\sqrt{2\over3}u$

(2) $v={u\over\sqrt{3}}$

(3) $v={u\over\sqrt{6}}$

(4) $v={u\over\sqrt{2}}$
more_vert
Finally I've got good question on collision topic

1 Answer

more_vert
 
verified
Best answer

Ans: (4) $v={u\over\sqrt{2}}$

Sol: From momentum conservation 

$mu\hat{i}+0=mv\hat{j}+3m\hat{v'}$

$\hat{v'}={u\over3}\hat{i}-{v\over3}\hat{j}$

From kinetic energy conservation

${1\over2}mu^2={1\over2}mv^2+{1\over2}(3m)\Big(\big({u\over3}\big)^2+\big({v\over3}\big)^2\Big)$

Solving $v={u\over\sqrt{2}}$

thumb_up_off_alt 3 like thumb_down_off_alt 0 dislike
more_vert
Thnx... Sir for your answer
more_vert
How can you apply conservation of momentum in y axis

Welcome to Jee Neet QnA, where you can ask questions and receive answers from other members of the community.


Join our Telegram group for live discussion.

Telegram Group

Subscribe our YouTube channel for video solutions with explanation.

YouTube Channel

Download Jee Neet QnA Books in PDF for offline learning.

Jee Neet QnA Books

1.2k questions

841 answers

383 comments

87 users

...