1. Energy
Part 6 - Power

2. Power is… …the rate at which energy is converted.
…the rate at which work is done. …P
…measured in Watts (W), which is J/s.

3. Power Equations P = ΔE/t P = W/t But, W = FΔx, so P = FΔx/t
And Δx/t = v, so P = Fv
ΔE = change in energy
t = time
W = work
F = force
Δx = displacement
v = velocity

4. Horsepower Defined by James Watt:
The amount of work a horse can do in one second.
One horsepower = 746 Watts

5. P = FΔx/t F=mg Pt = FΔx F=(50)(9.8) 200t = (490*5) F=490 N
A 50.0 kg student climbs 5.00 m up a rope at a constant speed. if the student's power output is W, how long does it take the student to climb the rope? How much work does he do? m=50 kg Δx=5 m P=200 W t=? F=? W=?
P = FΔx/t
F=mg
Pt = FΔx
F=(50)(9.8)
200t = (490*5)
F=490 N
200t = (2450)
t = (2450)/200
W = FΔx
t = s
W = (490)(5)
W = 2,450 J