Statement A: Work done by frictional force is always negative.
Statement- 8: A body at rest can have mechanical energy.

Work done by a frictional force is

Work done by a frictional force is

When work done by force of gravity is negative, then

Work done by friction in pure rolling is always zero. Is this statement true or false?

Work done by force of static friction .

The work done by kinetic friction on a body :

Statement-1: Work and Heat are two equivalent form of energy. Statement-2: Work is transfer of mechanical energy irrespective of temperature-differene whereas heat is transfer of thermal energy because of temperature difference only.

STATEEMNT-1 : Work done by frictional force is always either negative or zero. because STATEMENT-2 : Work done by the static friction on a system may be zero.

A : Work done by the frictional force can’t be positive. R : Frictional force is a conservative force.

The work done by a body against friction always results in