Centre of mass

Exploring balance and centres of mass can be great fun. The resulting structures can seem impossible. Here are some images to encourage you to experiment with non-breakable objects of your own.

Bricks are 20cm long and 10cm high. How high could an arch be built without mortar on a flat horizontal surface, to overhang by 1 metre? How big an overhang is it possible to make like this?

A cone is glued to a hemisphere. When you place it on a table in what position does it come to rest?

Invent shapes with different numbers of stable and unstable equilibrium points

Consider the mechanics of pole vaulting