What is the formula for elastic collisions?

Answer 1

if we assume m1 (mass) and v1 (velocity) for first mass , m2 and v2 for second mass ,we have : m1 v1i + m2 v2i = m1 v1f + m2 v2f and 1/2 m1 v1i2 + 1/2 m2 v2i2 = 1/2 m1 v1f2 +1/2 m2 v2f2 i : initial f : final

This is a simplified version: vf1= ((m1-m2)/(m1+m2))(v1i)+ (2m2/(mi+m2)vi2

Answer 2

You can use two equations to help you solve this type of collision.

1) Total momentum before the collision = total momentum after the collision. (This applies to all collisions, whether elastic or not).

2) Total kinetic energy before the collision = total kinetic energy after the collision. (This applies only for elastic collisions.)

An interesting detail is that in an elastic collision, the relative speed of two objects before the collision is the same as the relative speed after the collision.