1. Using machines

2. Compound machine- a machine made up of 2 or more simple machines.
Ex: an axe = wedge and lever

3. What simple machines make up these compound machines?

4. Efficiency- a measure of how much work put into a machine is changed to useful work.
Efficiency = W out / W in X 100
*Efficiency will be a percentage*

5. Power- rate at which work is done
Power- rate at which work is done. Measure of amount of work done in a certain amount of time.

6. Power Equation
Variable Ending Units
Power = P Watts (W)
Work = W Joules (J)
Time = t seconds (s)

7. W = P x t
P = W / t
t = W / P W . . P t x