2. Simple Machines
Simple Machines are tools that make work easier and have few or no moving parts. Most simple machines make work easier by trading the amount of force used with distance.
Simple machines require energy to do work.
We often use simple machines to move loads. A load is the object that you are moving such as a box of paper.

3. Types of Simple Machines
The 6 types of simple machines are:
The Pulley
Lever
Wedge
Wheel
Inclined Plane
Screw

4. Pulley
A pulley uses grooved wheels and a rope to raise, lower, or move a load. Many windows are raised and lowered using pulleys.
Pulleys make a change in the direction of the force that is applied to an object. A pulley allows you to pull sideways to lift an object.

5. Lever
A lever is a stiff bar that rests on a middle support. A lever, such as a see-saw, can be used to lift or move loads.
A lever trades force for distance. The longer the effort arm of a lever, the less force you will need to lift the load.

6. Wedge
A wedge has at least one slanted side that ends in a sharp edge. An axe blade is a wedge that cuts material apart.
A wedge reduces the amount of force you must use to split objects.

7. Wheel and Axle
A wheel with a rod through its center lifts or moves loads. The rod is called an axle. Cars and trucks have four wheels and four axles.
A wheel reduces the amount of friction an object must push against.

8. Inclined Plane
An inclined plane is a slanted surface. It is much easier to move an object up an inclined plane than straight up.
An inclined plane trades force for distance. It takes less force to walk up a ramp, but you must walk farther than going up stairs.

9. Screw
A screw is an inclined plane that is wrapped around a pole. Screws hold things together and can be used to lift materials.
A screw trades force for distance. It takes many spins of a screwdriver to put a screw in a board. Once it is in the board it would take a great force to remove it.

10. Simple Machines are used to solve problems.
People use simple machines everyday to help them solve problems.
Screws are used in construction and help hold objects together.
Levers help lift heavy objects.
Wheels help move objects around.
Inclined planes help move objects to higher places easier such as ramps.

11. Questions You May See On the EOG
Which kind of tool makes work easier and has few or no moving parts?
A. a complex machine
B. a simple machine
C. an axle
D. a pulley
What is an inclined plane that is wrapped around a pole also known as?
A. Wedge
B. Pulley
C. Wheel
D. Screw