Slides and steps
Is a slanted board a machine? It is if you use it to do some work. It’s
a kind of simple machine called an inclined plane. Inclined means
\”slanted,” and a plane is a flat surface. So an inclined plane is a
flat surface that slants, like a slide on a playground.
An inclined plane makes it easy to move things up and down. When you use
an inclined plane, you spread out the amount of work you do. If you lift
a heavy box onto a table, you move it only a short distance— straight
up. But you are doing all the lifting at once. If you slide the box up a
slanted board, or inclined plane, you have to move it farther to reach
the tabletop. But you do the lifting little by little, so the job is
easier.
Inclined planes are a help in moving heavy things. But there are other
ways to use them, too. When you wheel your bike up and down a bike ramp,
or take a ramp to get on or off an expressway, you are using an inclined
plane. And there are ramps at airports and other busy places for people
to walk up and down.
The kind of inclined plane you use most often may not look like one.
Stairs are an inclined plane! They are not the same smooth shape as a
slanted board or a bike ramp, but they help you work in the same way.
When you use stairs, you move on a slant. It’s not like climbing a
ladder that is straight up and down. The stairs are longer than the
ladder would be. But the climb is easier. You lift yourself a little at
a time.
