1. Work Power Energy

2. Work (Joules) = Force (Newtons) x distance (meters)
What is Work?
When a force causes an object to move
Measured in Joules ( J )
Work (Joules) = Force (Newtons) x distance (meters)
W( J ) = F (N) x d (m)
W = Fd

3. What is Work? No Movement = No Work:
No work occurs unless movement occurs
A force can be applied and energy can be used, but its not considered work unless motion also occurs

4. What is Work?
W = Fd
W = Fd
W = ? J

5. Work 167 N 100 N 10m 6m W = 167N x 6m W = 100N x 10m W = 1,000 J
Cyclist
Climber
W = 167N x 6m
W = 100N x 10m
W = 1,000 J
W = 1,000 J
same height = same work

6. Power
The rate at which work is done
Measured in Watts
Work
Time
Power =

7. How much power did each use?
Both the bicyclist and climber performed 1,000 J of work.
The bicyclist took 20 seconds to reach the top
The climber took 120 seconds to reach the top
How much power did each use?

8. Power
Work
Time =
Bicyclist Climber
1000 J
20s
Power =
= 50 Watts
1000 J
120s
Power =
= 8.33 Watts

9. Horsepower: Another Unit for Power 1 hp = 746 Watts

10. (Joules) = (Newtons) x (meters)
W = Fd
Work Summary
Work = Force x distance
W( J ) = F (N) x d (m)
Units of measure:
(Joules) = (Newtons) x (meters)

11. Power Summary W t P = (Watts) = P(W)= Units of measure: (Joules)
(seconds)
(Watts) =
Work
time
Power =
W (J)
t (s)
P(W)=