Simple Machines

Learning about science can be hard work, but simple machines can make it easier. Let Bill Nye push and pull you around ramps, levers, screws, and pulleys.

Simple machines simply make work easier by directing forces over distances. Instead of lifting a heavy box upstairs, you can hook it to some ropes and pulleys and pull it up. Or you can get a ramp and slide it upstairs. Either way, it’s less sweat to use the pulleys or the ramp than it is to lift the box straight up by yourself because the force you need is more spread out. Levers, ramps, screws, wheels, wedges, and pulleys are all simple machines designed to direct forces.

With simple machines we don’t have to push or pull as hard, but we have to push or pull over a longer distance. It’s easier to walk up a long set of stairs to the top of the Empire State Building than it would be to climb a ladder to the top, but the set of stairs would be much longer than the ladder.

Simple machines are simply scientific.

The Big Idea

• Simple machines can change the size and direction of forces.
• Simple machines make work easier for us by letting us push or pull over increased distances.

Did You Know That?

• The great pyramids in Egypt were built using earthen ramps?
• You have to use at least two pulleys to lower a pulling force?
• Complex machines are usually a combination of simple machines?

Books of Science!

• “The Science Book of Machines” by Neil Ardley. Published by Gulliver Books, 1992.
• “The Way Things Work” by David Macaulay. Published by Houghton Mifflin Company, 1988.