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A wooden block is kept n a polished wode...

A wooden block is kept n a polished woden plank and the inclination of the plank is gradually increased. It is found that the block starts slipping when the pland makes an angle of `18^@` with the horizontal. However, once started the block can continue with uniform speed if the inclination is reduced to `15^@`. Find the coefficients of static and kinetic friction between the block and the plank.

Text Solution

Verified by Experts

The coefficient of static friction
`mu_s=tan18^0`
and the coefficient of kinetic friction is
`mu_k=tan 15^0`
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