Spinning Yo-Yo Experiment

Procedure

Get a toy yo-yo and practice using it. Use a piece of clear tape to attach a piece of gum centered on the side. Leave the gum in the wrapper. Now use the yo-yo as you normally would. The gum will come shooting out of the wrapper.

Scientific Principle at Work
The spinning yo-yo, like any spinning object, creates a force on each part of it equal to mass times radius times the square of the rotation rate. In other words, the faster the yo-yo spins, the larger the force it creates. So the harder you throw the yo-yo, the further the gum will fly.

To make sure that tires are safe, even after they are flat, engineers designed a plastic disk that goes on the rim of the car tire. The rim is strong enough to allow the car to keep driving, even if the outside tire fails and is flat. Designers had to consider rotational physics to make sure that at high speeds the plastic insert would be strong enough not to fly apart inside the tire.