Question

A metal block of mass $100kg$ is dragged on a rough horizontal surface with a constant speed of $5m{s}^{-1}$. If the coefficient of kinetic friction between the block and the road is $0.4$. Find the rate of generation of heat in S.I. unit.

Answer 1

Loss of energy per unit time =work done by frictional force in a unit time

Heat generated $=\mu mgv$

$=0.4\times 100\times 10\times 5$

$=2000$

$=2kJ$