1. Simple Machines A. transferring a force from one place to another
I. What a machine can do:
A. transferring a force from one place to another
B. changing the direction of a force
C.  increasing the magnitude of a force, or
D. increasing the distance or speed of a force
What machines can’t do:
No machine can increase (multiply) both the force and distance at the same time.  Why?  Machines can't increase the amount of work done!  They just make the work easier to do.

2. Terminology
A. FE - the force applied to the machine
B. dE – effort distance, (usually, this is what the
person does)
C. dR - the distance that the object moves.
D. input work (WI = FE x dE)
E. Output work. (Wo = FR x dR).
F. MA can be expressed 2 ways: (Ideal)IMA = dE/dR does not take friction into
account
(Actual)AMA = FR/FE AMA < IMA

3. 1st Class Levers Have the fulcrum placed between the load and the effort. They always change the direction of the force. 
Input force
Output force
MA = E arm/R arm
Examples: scissors, seesaws , oars
and crowbars

4. 2nd Class Levers Does not change direction of the force. When the
resistance gets
closer to the
fulcrum, there is
an increase in
force (more MA).
Examples include nut crackers, wheel barrows, and bottle openers.
MA = E arm/R arm

5. 3rd Class Levers
Does not change the direction of force, always produces a gain in speed and distance and a corresponding decrease in force.
MA = E arm/R arm
Examples include tweezers, ice tongs,
fishing poles, mouse trap and shovels.

6. Wheel and Axle
A wheel with a rod, called an axle, through its center lifts or moves loads.
MA: The mechanical advantage of a wheel and axle is the ratio of the radius of the wheel to the radius of the axle.
Examples: rolling pin, door knobs, pencil sharpeners and bicycle

7. Pulley
Fixed – acts like a first class lever, changes direction of the force, you use the same amount of force
Movable – you can use less force but have to pull the rope through a greater distance
MA – count the number of strings (don’t count free end if pulling down)
Examples: flag pole, window blinds, rock climber pulleys, and block and tackle
and winch

8. Inclined Planes and Wedges
Examples
Inclined Plane – stairs,
ladders, and car ramps
Wedges – pin, chisel,
and nails
inclined plane - a slanting surface
connecting a lower level to a higher level. You can use less effort but have to move the force through a greater distance
Wedge – has at least one slanting side ending in a sharp edge MA
Inclined Plane MA = S/H
Wedge MA =Slope/Thickness

9. Screw A screw is an inclined plane wrapped around a pole which holds things together or lifts materials.
-MA – wrap string around screw and divide that length with the height of the screw
Examples:
-Jar Lids
-Light Bulbs
-Stools
-Clamps
-Jacks
-Wrenches