Push against a door that does not move. Describe the mechanical energy

Work done on the door is = 0

Mechanical energy of the person is 100%

Mechanical energy of the door is 50%.

Explanation:

Mechanical energy, M.E., is the energy an object possesses due to its position and motion. When we talk of position, the body is at rest = potential energy. In terms of motion, the body is moving = kinetic energy.

This means that M.E = potential + kinetic

Also, Work done = force × distance

For the person pushing the door, the potential of the energy stored in the person and the kinetics of pushing the door handle are all present. Therefore,  M.E of person is 100%.

But despite the doors potential energy present, there is no motion from it, which means the M.E is only half or 50%.

Also, since distance moved by the door is 0, no work is done on the door.