How can work done be Zero while you have tried & tried a lot & exhausted all of Ur energy?

Question

When one lifts with all his force &gets exhausted to pick up say a 500kg weight which doesnt move at all, the output work done = (force * distance) which is zero where did the input energy go??

Answer 1

The net work done is zero, but in the meantime you might have made minor displacements, a corner here lifted a mm or so, dropped instantly. Maybe even deformed the weight a bit.

Answer 2

Work equals force time distance. No distance, no work. The efficiency of the work equals the work actually accomplished divided by the energy expended. If the weight doesn't move, your efficiency is zero. The energy all goes into heating the room instead.

Answer 3

You've done (force•distance) on a microscopic scale within your muscles. The way our muscles are constructed, it requires energy just to keep them in a flexed state. If you could look into your muscle cells with a microscope, you'd see tiny back & forth motions against a force, and that's what drains the energy. You still have done no work ON THE BOX, however.

Answer 4

energy isn't destroyed even in this case... all living beings produce energy by burning glucose in their cells, which produces heat, and keeps your muscles in a moving condition. I the case that you have said, I would prefer you to do the experiment yourself, do it, and think, do you feel hot?? If its winter, you won't feel cold anymore, and you may start sweating in summers just by trying to move that heavy box, which you can not slide!!! It wasn't because you weren't working, but because force applied by you wasn't sufficient to overcome static friction, and thus energy produced by you is simply get dissipated by means of thermal energy (temperature of your body rises a bit!!!)

Answer 5

this is in the normal language we speak and connect to others.we see a coolie handling such heavy baggage and we say that he did a big job carrying those heavy things.but in mechanics work W=Fscos@ where F is the component of force, s is the distance and cos@ is the angle made between F and s.so if you take the example of the coolie, simply his work equation will be W=Fscos90 = 0.

Answer 6

w=fs
cos of the angle of inclination
if that is 90 degrees then force is parallel
terefore the work willbe done along 90 degeres and hence no work is done

Answer 7

Eh thermal energy?

Work done on the object?

Answer 8

You warmed up the room and yourself a bit.

Not my prefered method of burning calories, but if you enjoy it, feel free.