A long plank of mass M is initially at rest on a frictionless surface. A small block with mass m and initial speed `u_(0)` slides on top of the larger plank. The coefficient of friction between the block and plank is `mu` Net work done by friction if the top block falls off the plank after sliding over its length L isA. `- mumgL`B. `-mu((M+m)/(M))gL`C. `-mu((M)/(M+m))gL`D. `-mu MgL`

A long plank of mass M is initially at rest on a frictionless surface.

1.	A long plank of mass M is initially at rest on a frictionless surface. A small block with mass m and initial speed `u_(0)` slides on top of the larger plank. The coefficient of friction between the block and plank is `mu` Net work done by friction if the top block falls off the plank after sliding over its length L isA. `- mumgL`B. `-mu((M+m)/(M))gL`C. `-mu((M)/(M+m))gL`D. `-mu MgL`
Answer» Correct Answer - A

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