Material under tension

In many mechanical solution, the flexibility of materials is use as a function. Metal springs are a very common example of this. But almost any material can be loaded with tension and then used as a functional part. Make: magazine made this interesting video on how simple flat wooden sticks like popsicle sticks or tongue depressors can be used as if they where springs and cause a chain reaction. But there is no reason to stop there, almost any material can do the same. For example, we would love to see you make the worlds first spaghetti bomb!

Why does a wheel roll?

Do you know why a wheel roll? Because its circular? Well ok, it’s true, a wheel rolls because it is circular. But what if you need to make an object that isn’t circular, and still want it to roll? Then you need to understand the fundamental reason why circular things roll. Numberphile made this scientific video that explains in great detail how important the center of mass is, and how to use math in order to design rollable objects. In this case two discs wedged together serves as an example, but the physics applies to all objects.

If you don’t enjoy maths as much as we do, you can always skip to 10 minutes and 27 seconds, where Matt Parker (Mathematics Fellow at Queen Mary University of London) gives you the quick lazy version 🙂