Coefficient of Restitution

[CANorton]

Does anyone know how to calculate the coefficient of restitution between two particles from the two restitution values of the particles concerned?
As an example if the restitution value of one object is 0.6 and the restitution value of the second is 0.8 what is the value of the coefficient of restitution when the two objects collide?
I have tried to work out the formula that connects these values but failed.
Many thanks for any help.

[korry]

Hi,
I think, that it is multiplication - choose 0 for one particle and you will not see any bounciness. Only when coeficients of all particles will be 1, it will bounce "forever".
You will see same behavior if particles has 0,5 and 0,2 or 0,4 and 0,25.

[tatt61880]

As an example if the restitution value of one object is 0.6 and the restitution value of the second is 0.8 what is the value of the coefficient of restitution when the two objects collide?

The answer is sqrt(0.6 * 0.8) = 0.4 * sqrt(3) = 0.4 * 1.7320508... nearly equals 0.69

[CANorton]

The geometric mean! Now why didn't I think of that.
This is terrific and really useful.
Many thanks.