Types Of Collision - Practice Questions & MCQ

1. On the basis of conservation of kinetic energy

a. Perfectly elastic collision

• In this collision, $(K . E)_{\text {initial }}=(K . E .)_{\text {final }}$
  - Coefficient of restitution $\mathrm{e}=1$
  - Ex- Bouncing of ball with same velocity after the collision with ground.
  b. Inelastic collision
  - In this collision $(K . E)_{\text {initial }} \neq(K . E .)_{\text {final }}$
  - Coefficient of restitution $0<\mathrm{e}<1$
  - As $(K . E)_{\text {initial }}>(K . E .)_{\text {final }}$

The loss in  kinetic energy appears in other forms, such as heat , sound etc. 

Ex- Collision between two billiard balls. All majority of collision belong to this category.

c. Perfectly inelastic collision.

• If in a collision two bodies stick together or move with same velocity after the collision, the collision is said to be perfectly inelastic.

• Coefficient of restitution e = 0

• Ex-Collision between a bullet and a block of wood is an example of perfectly inelastic collision, if after collision the bullet remains embedded in the block, and block and bullet move together.

2.  On the basis of the direction of colliding bodies 

a. Head on or one dimensional collision

• In a head on collision the motion of colliding particles before and after the collision is along the same line .

b. Oblique collision

• If directions of motion of colliding particles after collision is not along the initial line of motion of colliding particles , then the collision is called oblique.

• Example : Collision of billiard balls.