Automatic A if You Answer This Question

[Fizzix]

"Automatic A if You Answer This Question"

My astronomy proffessor gave us this question in class today, and said anybody that could answer it would receive an automatic A. You would think that'd it be really hard but it doesn't look too dificult.

There is a block with mass "M" which is at a height "H" above a ball with mass "m." (M>>m) In an elastic collision where the block is dropped straight down onto the ball, at what height "h" will the ball bounce?

No quantities given.

//////////////////////////////////////////
/........./ M
/........./
//////////////////////////////////////////

l
l
l
l
H
l
l
l

.....m......

 

[cristo]

Well, I'm hardly going to answer a question that'll give you an A in a class am I?