Question

a person standing for a long time gets tired when he does not appear to do any work

Answer 1

As he utilizes the muscular force, His internal energy is used up, so a person standing for a long time get tired thought he does not appear to do any work as he is not moving.

I hope that I helped you
please mark me as brainliest

Answer 2

$\huge \bold\color{red}{AnsWer}$

A person standing still for a long time feels tired because the force of gravity acts on our body and puts stress on our muscles. so our muscles need energy to do work and keep body balanced and help to stand upright.