Simple Machines: Wheels and Axles (and gears)

I guess I didn't take any pictures of our wheel and axle activities, but I'll include a few links.

First of all, I thought it was interesting to think of a wheel as simply a type of lever—one that rotates around 360 degrees. This video I mentioned on the Screw post, plus this other video about wheels, were really entertaining and informative.

This page is full of good ideas for wheel-related activities. They also made a waterwheel, which is something we did during our water unit a few years ago. It's really fun.

We chose to study gears along with wheels, and here are some gear activity ideas.

Another gear video.

We also talked about ratios and how they relate to gears.

And just in case you've ever wondered what the difference is between a gear and a sprocket, you can find out here!

To show how wheels can help you measure things, we made surveyor's wheels or measuring wheels, sort of like these described here.

We looked at the gears on our bikes and noticed how, just like with levers, increasing the size of the spokes or pedals can change your mechanical advantage.

We watched a couple videos about how wheels are even used in the natural world! For example, these rolling salamanders and caterpillars use the principle of the wheel to escape from danger.

And these leaf-hoppers actually have microscopic gears to ensure that both their legs spring at the exact same time when they jump. Amazing!!

Simple Machines: Levers

Onto the second category of simple machines: levers! First, we just talked about levers themselves (wheels and pulleys had their own dedicated days). Levers are so fun to play with. We found examples of the different classes of levers around the house. Here's one site that gives a description of each lever class. We had several books on this.

I also think this popsicle-stick chain reaction would be a fun activity to do when studying levers!

We had a great time playing around with levers: changing the length, position of the fulcrum, etc., and seeing what happened. It was pretty easy to lift Goldie! :)

Harder to lift Seb.

Even harder to lift Abraham!

Next, we made catapults. Making catapults is always fun, but we particularly liked this new design we discovered. Some catapults we've made in the past are kind of flimsy, but this one was sturdy—and easy enough to make that even the littler ones could do it by themselves, once they saw how the basic triangle component was constructed. The guy that made up this catapult has a great website with notes on castles and sieges and other catapult designs to try. If we'd been making these for a Middle Ages Unit instead of a Simple Machines unit, we would have tried out some other designs too.

You can find another catapult design (using a spoon) here.

We shot marshmallows and Hershey's kisses with our catapults. Fun!

It was a pretty impressive way to see the power of a lever!

And here's a bonus picture of the children using some levers on the "Archimedes Playground" at the Museum of Natural Curiosity. Fun!