(i) Statement:

Algebraic sum of all the works done on a body is equal to change in the kinetic energy of the body.

$\therefore \Sigma W=\Delta K.E.$

(ii) Different works:

• By gravity = mgh

    h→vertical displacement.

• By friction = -F×s

    F→frictional force

    s→displacement along the frictional force.

    * work done …