Question

Why does work done not depend on time ?

If we take

W=F.s

=>W=ma.s

=>W=m(v-u/t).s....…………(I)

From this equation (I) we can conclude that work done is inversely proportional to time.

Is it correct?

Answer 1

Hi, Let me explain work a little.
work does not depend on time. you know why?
because you can take little time or lots of time to do the same work, that means to complete the same amount of work different machines will take different time.
like powerful machines will finish the same work amount in less time.
so Power depends on time not work.
if a machine takes less time to complete some work, it's more powerful. I hope you get the idea.
now coming to your derivation- W=m(v-u/t).s
here s/t = velocity or speed so basically work = 1/2 *m * v^2 which is also called as kinetic energy.
so basically work done depend on the speed at the moment or change in kinetic energy.

* I hope you understand above answer. if you have any more doubts, please make a fresh request.