Laws of motion

Question 1

Equation for objects that join together after a collision

Answer 1

m1u1 + m2u2= (m1 + m2)v

Question 2

Equation for objects that bounce off one another after a collision

Answer 2

m1u1 - m2u2=-m1v1 + m2v2

Question 3

How to calculate if a collision is elastic or inelastic

Answer 3

Before the collision
Ek= 1/2 x m1 x u1^2 + 1/2 x m2 x u2^2
After the collision
Ek=1/2 (m1 + m2) v^2