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Classical Mechanics Puzzle

January 30, 2012

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Michael L. Broide, Associate Professor and Chair of Physics, and Norman Paris, a former Visiting Assistant Professor, published their analysis of an intriguing physics problem involving the coupled motion of two blocks.  Their paper was the second-most read AJP article in December 2011.

Which Block Wins?
Block 1 sits on a frictionless table and is connected by a string to block 2.  When block 2 is released, it swings toward the table. Simultaneously, block 1 slides toward the pulley. Will block 1 hit the pulley before or after block 2 hits the side of the table?  The blocks are identical and start from rest equidistant from the pulley.  See American Journal of Physics for the answer and the details. 

AJP Fig 1