00:01
So in this problem, this is ground level and we are lifting an object of mass m.
00:10
We are putting this into an al mirror and the height increase is h.
00:17
Here also the speed is zero.
00:19
Here also the speed is zero.
00:22
Potential energy was something here and potential energy is something here.
00:26
So now if an object is there, definitely there would be a point.
00:31
Force mg acting downwards and in order to you know lift it you need to apply a minimum external force which is equal to mg in the vertically upper direction.
00:42
So this is the force applied by you and you are moving the object so you are producing this upward displacement h and you are always applying an upward force also which is equal to mg.
00:54
So the work done by you is force which is mg into h.
00:59
Since the force and displacement are in the same direction the work done by you is positive.
01:04
So when you are doing a positive work, definitely you are supplying the energy.
01:10
So where this energy is going actually? so this energy is definitely if you see the kinetic energy initially was zero finally is zero...