#### tiny-tim

Science Advisor

Homework Helper

- 25,789

- 242

Hi aloshi!

Compression is the opposite of tension (negative tension) … it means the sphere is squashed very slightly, and there is an

Tension and compression are stress when there are no shear forces (sideways forces).

Restitution is the restoring force when the sphere starts to expand again (back to its original size).

If the material is perfectly elastic, then the collision is also perfectly elastic, and

If the material is

The ratio is called the modulus of elasticity (or the coefficient of restitution).

See also http://en.wikipedia.org/wiki/Coefficient_of_restitution" [Broken]

Compression is the opposite of tension (negative tension) … it means the sphere is squashed very slightly, and there is an

*internal force*, just like the internal force of tension in a rope, but acting inward instead of outward.Tension and compression are stress when there are no shear forces (sideways forces).

Restitution is the restoring force when the sphere starts to expand again (back to its original size).

If the material is perfectly elastic, then the collision is also perfectly elastic, and

*no energy is lost*. The force of restitution is then the*same*as the force of compression.If the material is

*not*perfectly elastic, then energy i*s*lost, and the force of restitution is*less than*the force of compression.The ratio is called the modulus of elasticity (or the coefficient of restitution).

See also http://en.wikipedia.org/wiki/Coefficient_of_restitution" [Broken]

Last edited by a moderator: