Fantastic elastic

Stretchy things that spring back.

Spring back!

Stretch a rubber band, then let go. It goes back to its shape! Materials that do this are elastic.

Elastic materials store energy when you stretch them. That is how a catapult works.

Rubber comes from the milky sap of rubber trees. It is very elastic. Tyres, balloons and balls are made of rubber.

The sap is called latex. It is collected every morning and made into rubber.

A spring is a coil of metal. Squash it or stretch it – it springs back. Springs are in pens, beds and weighing scales.

Springs are found in pens, mattresses, cars and toys.

When a ball hits the ground, it squashes a little. It springs back into shape and bounces up!

Each time the ball hits the ground, it squashes and springs back up.