0

Currently, as described in this question, collisions cannot be elastic. However, is there a way to make a collision more elastic?

Background:

We're working on a project right now involving high speed energy transfer to an exercise ball. One of the issues right now is that the exercise ball is going far slower than what basic (e.g. AP Physics AB) calculations say they should be. I know that this is most likely due to the less-than-perfect elasticity of the collision between the ram and the ball. Is there any way to make the collision more elastic?

Community
  • 1
Snakes and Coffee
  • 225

2 Answers2

2

Extended objects are composed of order 10^23 atoms or molecules which are bound together with atomic forces vibrating in position and this vibration is a function of temperature. These vibrations for most materials are random in the 3 dimensional directions, push-pulling in every which way. But there exist materials that have by their internal structure elasticity.

elasticity is the tendency of solid materials to return to their original shape after being deformed. Solid objects will deform when forces are applied on them. If the material is elastic, the object will return to its initial shape and size when these forces are removed.

The physical reasons for elastic behavior can be quite different for different materials. In metals, the atomic lattice changes size and shape when forces are applied (energy is added to the system). When forces are removed, the lattice goes back to the original lower energy state. For rubbers and other polymers, elasticity is caused by the stretching of polymer chains when forces are applied.

In effect elastic materials behave like tiny springs: they are compressed at the impact and reflect the energy after it dissipates, at velocities that balls are played. If the material is rigid enough it could behave as almost a point particle and scatter mainly elastically.

To get more elasticity you should examine the materials and geometry of your balls and the needs of the game as far as catching the ball or being hit accidentally: balls that behave elastically with walls may injure severely humans and animals..

Community
  • 1
anna v
  • 233,453
0

Think about the characteristics of an elastic collision: what do the words mean?

For instance, coating the ball, and what you hit it with, in 0.25" hardened steel plate would make the collisions more elastic ;)

But for objects bigger than a bb pellet, it's quite difficult to minimize the dissipation.

Simon Bridge
  • 402
  • 2
  • 7