# Power supplied holding a mass suspended in air

1. May 25, 2014

### piisexactly3

A problem I thought would be very simple, but can't seem to get very far with.

Taking equations from textbook: Fv = P . Nope because velocity is 0 however power cannot be 0.
Using suvat: W = Fs , s = ut + .5gt^t , therefore P = Fgt/2 , this seems like the equation for how power would increase as an object falls but not the power supplied to keep it suspended which I imagine would be constant with time.

So there it is, leaving me very fustrated as it seems like it must be really simple.

2. May 25, 2014

Yes. Power=Fv and if it's velocity is changing(Accelerating at g), it's power should also change.

I don't think I understood you r question clearly. We don't need power,not even energy to hold things in place. Consider a book lying at rest on a table. No work is done there.

Edit. You can still use that equation. Since no distance is travelled when it's suspended, you can just plug in 0 into s in P=Fs/t

3. May 25, 2014

### piisexactly3

Ok but hold 50 kilos out in front of you and tell my why its tiring but no work is being done?

4. May 25, 2014