Simple Machines: Inclined Planes

Studying Simple Machines is one of those things every child has to do at some point, so there are tons of books, tons of lesson plans, and tons of other resources on how to teach about them. I don't think we did anything that extraordinary, but we had fun anyway. We spent a day on each type of machine, so I'll just show a few of the activities we did, most of which were suggested by books we read or lesson plans we found online.

Inclined Planes are a good place to start, since they're so basic, and they are one of the two larger categories that simple machines fall into. (The other being Levers.) We did some basic demonstrations, like dropping a hard boiled egg from a certain height and observing the force with which the egg hits the ground:

(a lot)

And then trying to find ways to reduce the force, using inclined planes. We managed to get some mostly uncracked eggs by rolling them down longer and longer ramps. It was a good way to illustrate the concept of trading force for distance.

We also measured force using a simple homemade spring scale (something like this).

We could see how a weight pulling straight down on the scale exerted a lot more force than a weight partially supported by an inclined plane.

Our favorite video explanation of inclined planes was this one. It's from a whole series on simple machines, but for convenience I'll link each machine's video on the corresponding blog post here.

Another thing I think would be fun to do for an inclined plane study is make a marble run out of toilet paper tubes and popsicle sticks, something like this. We have some marble run blocks, but it would be fun to experiment with how different angles of inclined plane allow the marble to reach different speeds, and how that affects the force and distance the marble achieves within the system.

This is a great lesson plan for learning about inclined planes. It also contains a good review/overview of forces and work, as those terms are used in physics.

If you want even more of a review, you can watch this video on friction and mechanical advantage—

and this one on work—

and this one on Newton's laws of motion.