Can You Equate Power to Energy Over Time?

[david smith]

Dear all

Can I say (and be correct):

Work done = energy used (work - energy theorem)

Power = Work done/time or P = f*d/t

and so

Work done/time = energy used/time and = Power

Therefore

ΔKE/t-(f*d)/t=0 => ΔKE/t - fv = 0 => P-fv = 0

Cheers Dave

 

[jtbell]

Yes, P = F·v is one way to calculate power.

 

[david smith]

Yes, P = F·v is one way to calculate power.

Yes but what I'm asking and didn't make very clear is, does power used = Δenergy/time?
So if you know f*v you can find the energy used.

Thanks, Dave

 

[haruspex]

So if you know f*v you can find the energy used.

Sure. E = ∫F.dx = ∫F.(dx/dt).dt = ∫F.v.dt
Bold indicating vectors, their products being the scalar product.

 

[david smith]

Sure. E = ∫F.dx = ∫F.(dx/dt).dt = ∫F.v.dt
Bold indicating vectors, their products being the scalar product.

Thanks