1. Simple Machines

2. Objectives 1. Name and describe the six types of simple machines.
2. What determines the mechanical advantage of different types of simple machines?
3. Recognize simple machines within compound machines.

3. Simple Machines - all complex machines are composed of combinations of these.
Lever Family
Simple lever
Pulley
Wheel and axle
Inclined Plane Family
Simple inclined plane
Wedge
Screw

4. Hammer

5. Pulleys

6. Pulley IMA
Is equal to the number of rope segments supporting the load

8. Wheel & Axle IMA
Is found by dividing the radius of the wheel by the radius of the axle.

9. Inclined Planes

10. An inclined plane
Reduces the effort force by increasing the distance through which the force is applied.

11. Wedge

12. Screw
An 87.5 kg nut and bolt, one of sixteen used to join sections of the generator shaft of a kW generator at Grand Coulee Dam in 1942

13. A screw
With closely spaced threads has a greater IMA than a screw with threads spaced farther apart.

14. Three Classes of Levers
1st Class 2nd Class 3rd Class

15. Mechanical Advantages of Levers
1st class can be < = or > 1
Seesaw, scissors, tongs
2nd class is always > 1
wheelbarrow
3rd class is always < 1
Baseball bat, hockey sticks, golf clubs