Energy Notes

Total Work = Fd Cos(θ)

KE = ½ mv2

Wnet = ΔKE = Δ½ mv2 = FnetdCos(θ)

PE = Potential Energy

ΔPE = mgh

Conservative Forces

A “Conservative Force” is once for which work depends only on the starting point and ending point.

We can define potential energy for any conservative force.

PEg = mgh

PEs = ½ kx2

Mechanical Energy = KE + PE

Conservation of Mechanical Energy

When only conservative forces act then:

KEI + PEI = KEf + PEf

Or KE + PE = constant

Nonconservative forces:

KEi + PEi + Wnc = PEf + KEf

Wnc = ΔKE + ΔPE

Conservation of Energy

Other forms of energy -> electric, chemical, radiant, nuclear & thermal.

KEi + PEi + Wnc + OEi = PEf + KEf + Oef

1 kcal = 4184 joules

__Power__

Power is the rate at which work is done.

## Power = Work/Time = Fd Cos(θ)/Time

Units in Watts.

1 Watt= 1 J/s

1hp = 746 Watts

1hp = 746 Watts

## No comments:

## Post a Comment