1. Power - The rate at which work is done
(8.1.1)
(2.3.5)
A person does 48 J of work in 6.0 s. What is their power output?

2. How much energy does a 75 Watt light bulb consume in a minute? (60 s)
4500 J

3. 1 horsepower = 745.7 Watts, 1 kW = 1000 Watts
My 30. HP van could go 25 m/s top speed. What was the force resisting its motion?
1 horsepower = Watts, 1 kW = 1000 Watts
890 N

4. Joe Mama does 613 J of work in 2.13 seconds. What is his power output?
P = W/t
= (613 J)/(2.13 s) = 288 W
288 W

5. Ima Wonder can put out 127 W of power
Ima Wonder can put out 127 W of power. What time will it take her to do 671 J of work?
P = W/t,
t = W/P = (671 J)/(127 W) = 5.28 s
5.28 s

6. What work does a 1.5 HP motor do in 1 minute? (3 hints)
(1 hp = w)
P = (1.5 HP)(745.7 W/HP)
t = 60 s
P = W/t,
W = Pt = ( W)(60 s) = J
67,000 J

7. Bob N. Frappels slides a box with 43 N of force at a constant speed of 5.3 m/s. What is his power output?
P = Fv
= (43 N)(5.3 m/s) = W = 230 W
230 W

8. Frieda People can put out 430. W of power
Frieda People can put out 430. W of power. With what speed can she push a car if it takes 152 N to make it move at a constant velocity?
P = Fv
v = P/F = (430. W)/(152 N) = 2.83 m/s
2.83 m/s

10. My son and I climbed from the Cold Springs campground on Mt Adams to the summit. We started at 7:00 am and got to the top at 1:00. I have a mass of about 75 kg, and was carrying an 18 kg pack with skis. What was my average power output if the elevation gain is 2030 m?
86 W