1. 6 Types of Simple Machines
Inclined Plane
Wedge
Screw
Lever
Wheel & Axle
Pulley

2. Inclined plane – flat, slanted surface.
When an object is moved up an inclined plane, less effort is needed than if you were to lift it straight up, but, you must move the object over a greater distance.

3. Examples of Inclined Planes

4. Ideal Mechanical Advantage
Ideal Mechanical Advantage = length of incline
height of incline

5. What is the Ideal Mechanical Advantage?
6 meters
2 meters

6. Wedge- Device that is thick at one end and tapers at the other
Wedge- Device that is thick at one end and tapers at the other. Most wedges (but not all) are combinations of two inclined planes.
A knife, axe, razor blade, and teeth are all good examples of wedges. Generally it can be anything that splits, cuts, or divides another object including air and water.

7. In each example identify what is being split or wedged apart by each wedge in the above pictures.
a rocket....
a fan...
a boat...
teeth...
Air
Air
Water
Food

9. Screws Screw- an inclined plane wrapped around a cylinder.
-changes the distance that you apply a force over
-the closer the threads are together, the greater the Mechanical Advantage.

10. Levers
Lever- rigid bar that is free to rotate (pivot) about a fixed point.
Examples- crow bar, door (hinge), sea-saw
Fulcrum- the fixed point that a lever pivots around.

11. 4. Three Classes of Levers Open Textbook to p. 391
1st Class Lever: fulcrum in center position
Example: Sea-saw, scissors
2nd Class Lever: output force in center position
Example: Door
3rd Class Lever: Input force in center position.
Baseball bat, rake

12. Lever Activity:
Objective- to compare the three types (classes) of levers. Open textbook to p. 391.
Create a First Class Lever
Place your index finger on the desk and balance the spoon on it.
Place bean in spoon bowl to represent output force.
Create a Second Class Lever
Place the spoon bowl on the table and one finger at end towards handle.
Where would bean go to represent output force?
Create a Third Class Lever
Where would your finger and bean go?

13. Mechanical Advantage of a Lever
MA = Distance from fulcrum to input force
Distance from fulcrum to output force

15. Wheel & Axel

16. Wheel and Axel
Simple machine made of circular or cylindrical objects, fastened together and rotate together.
The object(s) with the larger circumference (size) is the wheel.
The object with the smaller circumference (size) is the axel.

17. Wheel Axel

18. Distance of force is increased.
Mechanical advantage is usually greater than 1.

19. Mechanical Advantage of a Wheel
MA = Radius of Wheel
Radius of Axel

20. Gears Wheel with interlocking teeth.
Form a compound machine when more than one gear is used.

21. Pulley A grooved wheel with a rope, cable, or chain wrapped around it.
Direction of input force is changed.

22. Types of Pulleys Fixed Pulley- attached to a structure
Ideal Mechanical Advantage = 1
Movable Pulley- attached to the object you want moved
Ideal Mechanical Advantage = 2
Pulley System- combination of fixed and movable pulleys
Ideal Mechanical Advantage = 2 or more
The ideal MA of a pulley system is equal to the number of sections of the rope that support the object.

24. Pulley Systems Raising a Dumpster

25. Compound Machine A machine that utilizes two or more simple machines.
Example:
Wheelbarrow has a wheel and axel & lever

26. What are examples of Compound Machines?
Car
Wheel & Axel
Gears
Levers

27. Can Opener
Gears (wheel & axel)
lever

29. Screws Screw- _____________________________________
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