Simple machines are tools that make work easier. They have few or no moving parts. These machines use energy to work. The six simple machines are...
Lever: A lever is a simple machine. A lever is a board or bar that rests on a turning point. This turning point is called the fulcrum. An object that a lever moves is called the load. The closer the object is to the fulcrum, the easier it is to move. Here are some kids that explain a lever.
Here is an example of a lever being used to move a rock. The rock is the load. The place that the board rests on is called the fulcrum. Using this lever makes the work of moving the rock a lot easier.
Did you know that you have probably used a lever out on recess? These girls are using this simple machine to have fun on the playground. They are using the seesaw to make the work of lifting eachother easier.
Examples of Levers:
A hammer is a lever when it is used to pull a nail out of a piece of wood.
2. Inclined Plane
Inclined Plane: An inclined plane is a simple machine. It is a flat surface that is higher on one end. You can use this machine to move an object to a lower or higher place. Inclined planes make the work of moving things easier. You would need less energy and force to move objects with an inclined plane.
Examples of Inclined Planes:
Path up a Hill
3. Wheel and Axle
Wheel and Axle: The wheel and axle is another simple machine. The axle is a rod that goes through the wheel. This lets the wheel turn. It is easy to move things from place to place with wheels and axles. Here are kids that talk about wheel and axles.
You have probably seen a wheel and axle on a car. The axle turns when you put force on the wheel. Can you think of a different place that you might find a wheel and axle on a car besides what you see in this picture? How about the steering wheel or radio dials?
In this picture, this girl is pulling a wagon that has wheels and axles. This simple machine makes it easier to move these items. She would have a lot more work to do if she didn't have the wagon.
Examples of Wheels and Axles:
Gears in Watches, Clocks, and Bicycles
Screw: A screw is a simple machine that is made from another simple machine. It is actually an inclined plane that winds around itself. A screw has ridges and is not smooth like a nail. Some screws are used to lower and raise things. They are also used to hold objects together. Here is a kid ho talks about a screw
The girl in this picture is taking a lid off of a jar. Jars use simple machines to hold the lids on the top. When you turn the lid, it raises or lowers.
Where would I find an example of a screw?
Wedge: A wedge is a simple machine used to push two objects apart. A wedge is made up of two inclined planes. These planes meet and form a sharp edge. This edge can split things apart. Here's another kid talking about wedges.
You probably use a wedge at lunch every day. A fork is considered a wedge. A fork can be used to cut or split food apart. Can you think of another wedge you use to help you eat? (How about a knife?)
Examples of wedges:
Pulley: This simple machine is made up of a wheel and a rope. The rope fits on the groove of the wheel. One part of the rope is attached to the load. When you pull on one side of the pulley, the wheel turns and the load will move. Pulleys let you move loads up, down, or sideways. Pulleys are good for moving objects to hard to reach places. It also makes the work of moving heavy loads a lot easier. Here is another kid talking about a pulle
This crane uses a pulley to move the heavy wrecking ball. Without the use of a pulley, the wrecking ball would be very hard to move.
Examples of where pulleys can be used: