Let’s say you have a treehouse and you want your dog to join you there. Your dog can’t climb the ladder and you can’t hoist him up in a pulley. How could you get him up? Simple machines to the rescue again. This time an inclined plane can do the trick. An inclined plane is simply a board or other flat surface placed at an angle between two objects; in other words, a ramp. Fido can’t climb stairs but he could easily go up a ramp – just make sure it’s not too steep.
- Look around for inclined planes. Slides at the playground, wheelchair ramps, or ramps on moving trucks are all types of inclined planes. So are escalators and stairs.
- Inclined planes make work easier by spreading it over a larger distance.
- An inclined plane involves more distance than a straight route. For example, the ramp you made for your dog is probably much longer than the ladder to your treehouse, depending on how high in the tree your treehouse sits.
- Inclined plane: a ramp or other material placed at an angle between two objects
- Pulley: another simple machine that uses a rope threaded through a wheel or over a rod to lift objects
Questions and Answers
Question: Who invented the first inclined plane?
Answer: Keep in mind that unlike the pulley or lever, inclined planes are found in nature, e.g., a rolling hill. People probably figured out quite quickly that it was easier to walk or move goods up a low, gentle hill than a steep mountain. Archimedes first discussed the principles behind inclined planes around 200 B.C. Egyptians used ramps to heave rocks to the top of their pyramids.
Watch Sid the Science Kid explain more about inclined planes.