1. Work & Power

2. The object has to move some distance.
Work
For work to occur two things must happen:
The object has to move some distance.
The object has to move in the same direction as the applied force – only the force acting IN THE SAME DIRECTION as the object’s motion is performing work.

3. Calculating Work Formula: W = (F)(d)
The amount of work done depends on BOTH the AMOUNT OF FORCE exerted and the DISTANCE THE OBJECT MOVES.
The amount of work can be determined by multiplying FORCE times DISTANCE:
Formula: W = (F)(d)
W = work
F = Force
d = Distance

4. Calculating Work SI Unit of Work = Joule (N*m)
When force = NEWTONS (N)
When distance = METERS
Joule (N*m)
Named after James Prescott Joule an physicist from the mid 1800’s who studied work
1 Joule =1 Newton of force to move an object 1 meter
Joule is abbreviated with as J

5. - What Is Work?
The Meaning of Work
Work is done on an object when the object moves in the same direction in which the force is exerted.

6. Power Work is UNAFFECTED BY TIME
Power is the rate (time) at which work is done.
how fast or slow work is done
Power equals the amount of work done on an object in a unit of time.
With more power you can do the same amount of work in less time.

7. Power = force x distance
Calculating Power
Formula to calculate power:
Power = Work
Time OR
Power = force x distance

8. When work is measured in joules, and time in seconds:
SI Units for power: Joule/second (J/sec)
1 Watt = Joule/Sec. (J/s)
James Watt & His Steam
Engine

9. Units of Power One watt is a small amount of power
Power is more often expressed in KILOWATT
Kilowatt = 1000 watts
Horsepower: English Unit (not an SI unit)
1 HP = 746 Watts
Corvette

10. Quick Summary: What is work? How can you calculate work?
Question
Answer
Work is done when an object moves in the same direction in which the force is exerted.
What is work?
How can you calculate work?
Work = Force X Distance
Power is the rate at which work is done.
P = work / time
What is power?