Explain how work done by a variable force may be measured.

Work done by frictional force

Work done by a frictional force is

Work done by a spning force is

Now work is done by a force on an object if

Obtain graphically and mathematically work done by a variable force.

How is work done by a force meaured ?

Assertion :- Work done by frictional force may be sometimes path independent. Reason :- Frictional force is a non - conservative force.

Statement -1: The work done by all forces on a system equals to the change in kinetic energy of that system . This statement is true even if nonconservative forces act on the system. Statement -2: The total work done by internal forces may be positive.

Work Done By Gravitational Forces