1. Power is the rate at which work is done.

2. Answer Me!!!
What does it mean to be powerful?

3. Power Power is the rate at which work is done.
Since you know that v = d/t:
Power is measured in J/s or Watts (W)

4. Practice Problem 1
A 3 kg block is initially at rest on a frictionless horizontal surface. The block is moved 8 m in 2 seconds by the application of a 12 N horizontal force. What is the average power developed while moving the block?

5. Practice Problem 2
A 4.0x103 W motor applies a force of 8x102 N to move a boat at a constant speed. How far does the boat move in 16 seconds?

6. Practice Problem 3
A motor having a power rating of 500 W is used to lift an object weighing 100 N. How much time does the motor take to lift the object a vertical distance of 10 m?

7. Practice Problem 4
What is the average power developed by a motor as it lifts a 400 kg mass at constant speed through a vertical distance of 10 m in 8 seconds?

8. Practice Problem 6
If the time required for a student to swim 500m is doubled, the power developed by the student would be
Halved
Doubled
Quartered
Quadrupled

9. Final Thought…
A motor having a maximum power rating of 8.1x104 W is used to operate an elevator with a weight of 1.8x104 N. What is the maximum weight the motor can lift at an average speed of 3 m/s?