Introduction Have you ever played with a Slinky, used a pinball machine, written with a click pen or ridden in a car? If so, then you have made use of a spring! Springs are in machines all around us ...

The two types of scales: a Hanging Scale and a Floor Scale. The Hanging Scale using a Rack and Pinion Gear and two springs to tell us how far much weight is on the scale. The Pinion Gear turns and ...