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Homework Statement
From Kleppner and Kolenkow:
A small cube of mass m slides down a circular path of radius R cut into a large block of mass M, as shown. M rests on a table, and both blocks move without friction. The blocks are initially at rest, and m starts from the top of the path.
Find the velocity v of the cube as it leaves the block.
Ans. clue. If m=M, v=√(gR)
http://img390.imageshack.us/img390/5575/blocksbi2.jpg [Broken]
Homework Equations
KE=(1/2)mv2
PE=mgh
mivi=mfvf
KEi=KEf
The Attempt at a Solution
For m, initial energy PEm=mgR
Just before m leaves block M, KEm=(1/2)mv2=mgR
Thus, v=√(2gR).
From here, I set up equations for conservation of momentum as well as kinetic energy.
I then used substitution and tried to solve for the velocity of m as it leaves the block, M, but the algebra just isn't working out. Did I make a mistake?
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