Coefficient of Restitution and Elasticity

  • ME6.1 Happy and Unhappy Balls     HappyAndUnhappyBalls

    This is a rather cute demonstration. Two balls of equal dimensions react differently when thrown to the ground. Happy ball, made of neopreme rubber, will bound back up. Unhappy ball, made of norbornene, hits the ground and stays there.

  • ME6.2 Objects Falling onto Plates     ObjectsFallingOntoPlate

    Balls of different material (chrome steel, nylon, glass, wood, brass, lead, aluminum, and rubber) are dropped onto a plate at inside a graduated cylinder. The height to which it bounces up can be measured on the cylinder. The cylinder also prevents the balls from rolling all over the lecture center.

  • ME6.3 Flexible I-Beam (PASCO)     ibeam_thumb

    This flexible I-beam is made of plastic so it can be visibly bent by hand. It shows the basic reasons for using this cross-section in construction. It is four times as stiff in the upright orientation as it is sideways. The beam does not sag under its own weight and returns to its original straightness after bending. Warming the beam makes it less stiff and cooling makes it more stiff.