The system is pulled to an elongation A and Then released. Find the minimum value of coefficient of friction between m and M for which m doesn't slips over M.

Explanation

`a larr`
`f larr m`
f = ma
`rArr" "f_(max) = m.a_(max)`
`rArr" "mu_(min) N = m omega^(2) A = (mkA)/(M + m)`
`rArr" "mu_(min).mg = (mkA)/(M+m)`
`rArr" "mu_(min) = (KA)/((m + M)g)`