1. What is mechanical advantage?
The force you apply to a machine is called the effort force (input force)
The force that the machine applies is the resistance force (output force)
To open a can, you apply a force of 50 N to the can opener. The can opener applies a force of 775 N to the can.
The machine multiplies your effort force so work becomes easier
A machine lets you use a small force to overcome a large force
The number of times a machine multiplies the effort force is called its mechanical advantage

2. How to calculate mechanical advantage:
MA = resistance force ÷ effort force
The resistance force is often equal to the weight of an object being moved
EX: To crack a pecan, you apply a force of 50 N to the nutcracker. The nut cracker applies a force of 750 N to the pecan. What is the MA?
MA = RF ÷ EF
MA = 750N ÷ 50N
MA = (no units used)
The higher the mechanical advantage, the easier work is!

3. Calculate Mechanical Advantage:
You apply a force of 100 N to a pulley. The pulley applies a force of 800 N to lift a boulder. What is the mechanical advantage? RF ÷ ÷ MA X EF

4. How to determine MA of a lever
Every lever has two parts, an effort arm and a resistance arm
The effort arm is the distance from the effort force to the fulcrum
The resistance arm is the distance from the resistance force to the fulcrum
MA = effort arm length/ resistance arm length
(input)
(output)

5. Finding MA for a Fixed Pulley
Fixed pulleys only change direction of the effort force, not the amount
The effort force is equal to the resistance force
As a result, the MA of a fixed pulley is always equal to 1
Ex: If the effort force = 20 N and the Resistance force = 20 N, what is the MA?
MA = RF ÷ EF
MA = 20N ÷20N
MA = 1
A fixed pulley’s MA always = 1

6. Finding MA for Moveable Pulleys and Pulley Systems
You can find the MA of a moveable pulley by counting the number of ropes that lift the resistance
A pulley system is made up of both fixed and moveable pulleys
The pulleys are used together to increase the MA of the system
The MA of a pulley system is equal to the number of supporting ropes
MA = 2

7. The MA of a pulley system is equal to the number of supporting ropes Determine the MA of each pulley system:
MA = 2
MA = 3
MA = 4

8. Finding MA of an inclined plane (ramp)
You can find the mechanical advantage of an inclined plane by dividing its length by its height
MA = length / height
MA = 3 m / 1 m
MA = 3
Length
Height