Question

if a body is displaced through height h, workdone will be -mgh.but when we see in interconversion of energy it take P.E=mgh

Answer 1

Answer on Question #48655 – Physics - Mechanics | Kinematics | Dynamics

if a body is displaced through height $h$, workdone will be -mgh. but when we see in interconversion of energy it take $P.E = mgh$

Solution:

Work done by the our force is negative in this case. This is the case where the force opposes the motion (body is attracted towards the centre of earth due to force of gravity), we apply force to move the body to the height $h$.

$$W = -mg \cdot h$$

But the potential energy is always positive because there is a height $h$ above the initial level:

$$P.E. = mgh_{initial}$$

http://www.AssignmentExpert.com/