1. 5.3 Simple Machines

2. 6 Types

3. Lever A bar that is free to pivot about a fixed point (fulcrum)
: the fixed point
: distance from the fulcrum to where the effort force is applied.
: distance from the fulcrum to where the resistance force is applied

4. 3 Classes of Levers

5. First Class Lever Used to , always changes the of the applied force.
Ex. Screwdriver used to pry paint can lid
Fulcrum is in the

6. Second Class Lever Always – does not change direction of force.
Ex. Wheelbarrow
Resistance is located between the

7. Third Class Lever
Increases the over which the resistance force is applied. (Does not multiply force)
Ex. Baseball bat or hockey stick
Effort force is

8. Mechanical Advantage Lever IMA = length of effort arm
length of resistance arm
Making the effort arm increases the IMA.

9. Pulley Fixed Pulley: modified first class lever Moveable Pulley:
Attached to ceiling or wall
Changes
Moveable Pulley:
Multiplies
IMA =
Distance you pull is the resistance distance

10. Pulley (cont.)
Block and Tackle
System of
IMA =

11. Wheel and Axle Machine with that rotate together (gears)
Ex. Door knob
IMA = radius of wheel
radius of axle
Can be increased by making the

12. Inclined Planes Sloping surface Reduces the IMA = length height
*the the ramp the less force required

13. Screw Inclined plane wrapped around a cylinder.
The closer together the threads, the easier to screw into wood

14. Wedge
Inclined plane with one or two sloping sides
Changes the

15. Compound Machine Two or more simple machines used together.
Ex. Can opener
Car