Simple machines are used to make work easier. They are known as "simple machines" because they require only a single force to perform a task. Schools require that students learn about simple machines within the science curriculum. Luckily, the physics of simple machines is an interesting science topic that most students enjoy. Demonstrate simple machine use through a series of easy science projects.
Lever and Fulcrum
A lever and fulcrum is a type of simple machine that allows heavy objects to be lifted with little effort. The see-saw is the best example of a lever and fulcrum. The lever is the straight metal piece, while the fulcrum is the point underneath the lever. For the purposes of a science project, your students can move a fulcrum to different points underneath a lever and see how much work is needed to lift an object. Have students place the fulcrum at one end, then the middle, then closer to the end where the weight rests. Simply press down on the end of the lever opposite the weight to feel the different levels of resistance.
An inclined plane is a flat surface that is set at an angle. Science has proven that it's easier to move a heavy object up the inclined plane. There is greater distance, but less resistance when moving a heavy object. To test this principle, find a sturdy, adjustable ramp and a loaded cardboard box. Set the ramp at it's highest point, then have students take turns pushing the box up the ramp. Gradually lower the ramp to a more horizontal surface. At what height was the box easier to push?
A pulley is a type of simple machine, containing a grooved wheel, which allows a person to use half the work it would normally take to lift an object. Ropes are strung through the groves to create the pulley system. Set up your own pulley system in the classroom. You need a pulley wheel, a rope and a hook to tie onto one end of the rope. Hang the pulley wheel from a sturdy beam. String the rope through pulley wheel. Tie the hook to one end of the rope. Attach a weight to the hook. Let students take turns pulling the end of the rope (opposite the weight) to lift the weight. Be sure to let students lift the weight without the pulley system as well. This allows them to feel how much work the pulley is doing.
Wheel and Axle
A wheel and axle consists of a bigger wheel attached to a smaller wheel, known as an axle. The bigger wheelspins around the axle, creating movement. Good examples of this include a Ferris wheel, or bicycle wheel. Make the use of a wheel and axle an interesting science project. Have students slip pencils inside empty threading spools to create mini wheel and axles. Place two to three of these mini wheel and axles underneath a book. Move the book back and forth, across a tabletop. Is it easier to move the book using the wheel and axles?