I have doubt wether option A is correct or not .

# Doubt in Conservation of Momentum

I think C,D is the answer.

yes it seems to be correct

plzz confirm

I dont have answer key. Can you give proof why A is correct

According to me it is coming BCD and doubt on A

@Sneha_2021 I’m sorry , i meant it’s incorrect, I don’t know how i typed it as correct instead of incorrect

There can be any number of collisions

yes sir their may be infinite collision to...

Sir can you send proof of why option A is incorrect and also why option B is incorrect

I correct my self

Actually U can thing in a reasoning way its not the proof but gives the correct reasoning

Lets suppose m1 and m3 are very large as compared to m2 ..now since collison is elastic then after m2 collides with m3 ..m1 rebounds with almost the same velocity whereas m3 gets very less velocity now in the same fashion m2 again collides with m1 and rebounds with almost no loss in velocity ...and again collides with m3 moving very slowly toward right....

And the pattern continues...

Hence There can be more than 2 collisons

For option A you can solve either mathematically , or you can analyse the situation, which is as follows

As m3 keeps on increases it’s velocity after collision keeps on decreasing whereas, velocity of m2 keep on increasing in opposite direction

Then again if m1 increase then then after collision the velocity of m2 in direction of m3 increases and hence there can be multiple collisions

For eg if m1, m3 tends to infinity then they act like wall , so now m2 will move to and fro between the walls and there will be infinite collisions

Option B seems correct to me!

According to me BCD are the correct options

Yeah, B is correct. I messed up a minor calculation there.

@Abhishek_2020_5 if option C and D are correct acc to you then B should also be correct because with these velocities 3rd collisions can’t take place