Every so often I like to pose a STEM challenge to one or both of my kids. We've done some really fun challenges like building bridges strong enough to support 100 pennies with just 3 notecards and some tape. I recently ran across a post where they used a clothesline and pulley to construct a Lego zip line.
Since the kids' nana had just recently given them a set of Classic Legos, this seemed right up E's alley. And boy, was I right!
First we looked for a plastic clothesline pulley at Walmart, but they didn't have any. Then we went to a small local hardware store, but only found expensive metal ones. So we tried a big name hardware store and finally hit the jackpot!
Next he had to build a platform and figure out how to attach it to the pulley.
Then he tested his contraption and discovered it arrived at its destination too forcefully. In fact, it smashed to smithereens! So he contrived a way to slow and pad the landing by wrapping a paper towel around the clothesline a foot or so from the end. During this phase we had a lot of great discussions about angles, gravity, force, friction, tension, and construction stability.
Lastly he decided to add a mechanism to assist in pulling the zip cart back to the start. You could avoid this step if you anchor the higher end of the clothesline a bit lower, but ours was high enough that Mister E needs a stool to reach it. He tied a piece of leather thong to the underside since that's what he had at hand.
Once the construction phase was complete, E played with his device for hours and hours on end. I was amazed with how long it held his attention. He kept coming up with new treacherous scenarios for his Lego man to overcome.
If you give this challenge a try, find me on Facebook and share a picture! We'd love to see what you come up with.