A man pushes an object how much work is being done by the object

Question

Suppose I push a box I know that the work done by me would be $ΔK$ but what would be the work done by the object itself, wouldn't it be negative as the force and displacement are at angle of 180°

DanDan0101 · Accepted Answer

By Newton's third law, the box does $-Delta K$ work on you.

TheImperfectCrazy · Answer

Lets invoke Newtons third law here.
You push a box and the box pushes you with equal but opposite force.
Note that you are exerting a force on the box and the box on you. The box is not exerting a force on itself.
To show that the force on itself is always zero, use Newtons third Law again. Suppose one end of the box pushes the other end, but the the other end pushes back with equal but opposite force. Hence the net force on the object by itself is always zero.
Hence by definition a box cannot do work on itself.

A man pushes an object how much work is being done by the object

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