1. Warm-Up 10/24/13
Complete the table below by looking at pg in the textbook
Figure
Direction of Force
Direction of Motion 1 2A 2B 2C

2. Work and Power
Thursday 10/24/13

3. What is Work? Work= the product of force and distance
The force must act in the SAME direction that the object moves.
No movement=No work

4. Arm & Ball moving in same direction,
No motion, No work
Arm & Ball moving in same direction,
Work is being done

5. Calculating Work Work = Force x Distance W=Fd
Units= N•m, also called Joules (J)
Work = Force x Distance
W=Fd

6. Example
How much work is done by a gorilla that lifts a 1000N rock over his head? Assume the rock was lifted to a height of 2 meters.

7. What is Power? Power= the rate at which work is done.
It takes MORE POWER to do WORK FASTER
Power can be increased by
Increasing the amount of work done
Decreasing the amount of time

8. Takes a long time
Slow rate
Low power
A lot quicker
Fast rate
High power

9. Calculating Power
Units= J/s, known as Watts (W)

10. Example
How much power is required to lift a box with a force of 72N to a height of 1.0meter in 2.0 seconds?

11. Your Job
Complete the Work and Power Practice Problems for tomorrow!