KVPY SA Exam 2012 Question Paper

A block of mass m is sliding down an inclined plane with constant speed. At a certain instant ${\mathit{t}}_0$, its height above the ground is h. The coefficient of kinetic friction between the block and the plane is µ. If the block reaches the ground at a later instant ${\mathit{t}}_{\mathit{g}}$, then the energy dissipated by friction in the time interval $\left({\mathit{t}}_{\mathit{g}}-{\mathit{t}}_0\right)$ is