Coefficient of kinetic friction and coefficient of static friction between two blocks is ${\mu }_{\mathrm{k}}$ and ${\mu }_{\mathrm{s}}$ respectively. In general

A block of mass $10 \mathrm{kg},$ moving with acceleration $2 \mathrm{m} {\mathrm{s}}^{-2}$ on horizontal rough surface is shown in figure

The value of coefficient of kinetic friction is

A particle of mass $2 \mathrm{kg}$ is moving in circular path with constant speed $20 \mathrm{m} {\mathrm{s}}^{-1}.$ The magnitude of change in velocity when particle travels from $A$ to $P$ will be

A particle is revolving in a circular path of radius $2 \mathrm{m}$ with constant angular speed $4 \mathrm{rad} {\mathrm{s}}^{-1}.$ The angular acceleration of particle is