Conservation of mechanical energy

AI Thread Summary
The discussion revolves around a physics problem involving two blocks connected by a massless string over a frictionless pulley. Block 2, which is lighter, is released from a height, and the goal is to determine the speed at which both blocks meet at the same height. The conservation of mechanical energy principle is applied, equating initial and final mechanical energy states. The key challenge is finding the unknown height "h" where the blocks meet, with the insight that one block descends while the other ascends by the same distance. The problem is clarified with the understanding that the heights of the blocks are interdependent during their motion.
nvictor
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Homework Statement



I have two blocks attached by a string (massless) over a pulley (frictionless, massless). Block 2 (which weighs less than block one) is released and the two blocks meet momentarily at the same height. I have the find the speed at which the meet at that moment. The blocks are separated by a distance of 1m.

I have drawn a figure in paint (sorry for this pic): http://i36.tinypic.com/2076at1.png

Homework Equations



Emechf = Emechi
Emech = Ug + K

The Attempt at a Solution



Emechf = Emechi
<=> (m_1gh + m_2gh) + (1/2m_1v^2 + 1/2m_2v^2) = m_1gH (where H = 1m, and h is the height at which they meet)

But then I have this h which is unkown and I can't figure out.

Thanks a lot in advance.
 
Physics news on Phys.org
If the lower (and lighter) block starts out at height "h", the higher (heavier) block starts out at height "h + 1".

At what height will they meet? Hint: One block lowers by the same distance that the other rises.
 
Thanks a lot, I see it clearly now. I really appreciate you help.
 

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