Two particles colliding and then separating

Section 1: Collision and Separation of Two Particles

Understand that two particles colliding means they come into contact, exert forces on each other, and subsequently separate.
Note that the two particles may have different masses and velocities before and after the collision.
Be aware that these collisions can be elastic or inelastic, affecting the conservation of kinetic energy.

Section 2: Conservation of Momentum

Remember that the principle of Conservation of Momentum applies to the collision and separation of two particles.
Know that the sum of the product of mass and velocity of both particles before the collision equals the sum of the product of mass and velocity of both particles after the collision.
Familiarise with the way to calculate the total momentum before and after the collision for both particles.

Section 3: Coefficient of Restitution

Understand that the Coefficient of Restitution (e) helps describe the collision behaviour when particles separate.
Learn to use the formula e = (relative speed after collision) / (relative speed before collision) when dealing with two colliding and then separating particles.
Note that the coefficient determines how ‘bouncy’ the collision is, with ‘e’ value closer to 1 being more elastic, resulting in less energy loss.

Section 4: Problem-Solving

Master using simultaneous equations to solve problems surrounding the collision and separation of two particles, involving both the conservation of momentum and the coefficient of restitution.
Practice free-body diagrams to visually understand the various forces in action at the point of collision and separation.
Become comfortable with vector notation when dealing with direction and magnitude of velocities and forces.
Regularly test your understanding of the principles, formulas and problem-solving methods through ample problem drills.