1. Simple Machines

2. Simple Machines!
Simple Machine-a device that makes work easier
Six types- inclined plane, wedge, screw, lever, wheel and axle, pulley
All simple machines transfer force.
Direction and/or magnitude
Even though simple machines use less force to move an object, it will be over a greater distance. OR
Simple machines can allow you to move further faster but with more force.\
Mechanical Advantage Formula:
MA=Force Out/Force Inn

3. Simple Machines Inclined Plane- a flat surface that slopes Ex. ramp
Only simple machine that does not move
Trade-Off for less force is greater distance.
This is how Egyptian Pyramids were made!

4. Simple Machines Wedge- an inclined plane that moves
Used to split or lift objects
It takes less force to drive into or under an object than it does to separate or lift the object yourself.
Two inclined planes put together
The closer the angle of the plane the sharper the object.
Examples: knife, fork, nail points, plows, axes, scissor blades and saws

5. Simple Machines Screw- an inclined plane wrapped around a cylinder
Thread- spiral ridges outside of the cylinder
As the screw is turned the thread pull the object up the shaft.
It takes less force to turn a screw than to pound a nail the same size.
The more threads there are on the screw the longer the incline so the easier it is to turn.

6. Simple Machines
Lever- long rigid bar that rests on and pivots around a fulcrum
Fulcrum-support for a lever
Effort-force applied to the lever
Load- force at the part of the lever which needs to be moved
There are 3 types of levers: First-class, Second-class and Third-class.

7. Lever
First-class- Fulcrum is near the center with the force and load at opposite ends
Examples-scissors, seesaw, pliers

8. Lever
Second-class-The load is in the center with the effort and the fulcrum on opposite ends.
Examples- nut crackers, wheel barrow

9. Lever
Third-class-effort in the center with fulcrum and load on opposite ends
Example catapult, human arm, hoe

10. Simple Machines
Wheel and Axle- consists of a shaft (axle) inserted through the middle of a wheel.
The difference between the size between the wheel and the axle caused the force to get magnified.
Examples, bicycles, ferris wheels, steering wheel, door knobs, wrenches

11. Simple Machines
Pulley-a wheel with a rope (or chain) wrapped around it
The wheel rotates on a fixed axle.
When the rope is pulled the wheel turns
Two types of pulleys: fixed, movable.

12. Pulley
Fixed pulley- one end is tied to an object so that pulley does not move

13. Pulley
Moveable Pulley-has a free axle and is used to redirect the force.

14. Pulley Block and tackle- a system of pulleys
Using more than one pulley reduces the amount of force needed to lift the load.