I have a new situation: Andy is playing with a rubber band. He stretches the rubber band out as far as he can without breaking it  But I can use this background: Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity . As you stretch or compress an elastic material like a bungee cord, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force . The farther the material is stretched or compressed, the greater the elastic force becomes. As soon as the stretching or compressing force is released, elastic force causes the material to spring back to its original shape. You can watch a demonstration of elastic force at this URL:  What is an answer for this question: Given a spring, will compressing it down cause it to stay compressed or return to its original shape?

original shape