# Hard Problem in Collisions

Two bodies of masses M and m (M > m) are attached to the two ends of a light inextensible string passing over a frictionless pulley. The system is held at rest with the string taut and vertical with both masses at a height 'd' above an inelastic table. The system is now released. Calculate the height to which the larger mass will rise after it has hit the table.

quickly pls.......

62
Lokesh Verma ·

umm... this will have a few things

1) the ball will reach the bottom with some velocity.

2) Then the ball will "not" bounce back.

3) During some time , the other mass (smaller) will move with the string not being taut!

4) Once the string becomes stretched then the accleration will change again.

Use these four things to reach the answer

33
Abhishek Priyam ·

The table is inelastic ?

62
Lokesh Verma ·

I edite the post accroding to pryam 's observation.. he caught me napping :)

1
Akand ·

nishanth i dint quite understand u..... the system has 2 masses with a string on a pulley....... so d bigger mass falls down followed by the small mass...............so from wher did d ball cum as u said in the solution??????
man my diagram is so dumb heheh

62
Lokesh Verma ·

sorry man.. i mean the masses.. u know how different masses are same as point masses.. and then balls are also like point massess.. and then you tend to use them interchangably .. just bcos in the end that doesnt make any difference :)

;)

62
Lokesh Verma ·

or atleast in this problem ;)

1
Thedarkknight ·

could someone pls tell the exact answer they got?

1
Akand ·

oh ok......... i thought u said tht the two masses joined and became a ball........hehe so dumb of me.........and nice ques kingb!!!

1
Akand ·

Dude kingb........understanding d ques itself is becomin a problem....and u r expectin an answer???? hehe just kiddin......

1
dimensions (dimentime) ·

but in que it is not mentioned that table is perfectly inelastic. so their must be some coeff. of restitution.rt?????????/

62
Lokesh Verma ·

I think it is meant that it is perfectly inelastic! but then yeah ur point is right dimensions...

@king sorry budy went for dinner.. will be on your problem at once

62
Lokesh Verma ·

@king.. i forgot that you will have to use impulse at one place :(

Sorry..

I am solving it.. sorry for the delay :)

62
Lokesh Verma ·

i got

dm2/(M+m)2