Question

Identify the conditions for an elastic collision in a closed system. Check all that apply.

Answer 1

Answer:

Energy is conserved

Momentum is conserved

One object may be stationary before an inelastic collision

Answer 2

Answer:

In an elastic collision:

• There is no external net force acting. Thus, Momentum before and after collision is equal. Momentum remains conserved.

• Total energy always remains conserved as energy cannot be created nor destroyed. It can change from one form to another.

• There is no lost due to friction in elastic collision. So the kinetic energy is also conserved.

• Velocities may change after collision. If the masses are equal, the velocities interchange.

When one object is stationary:

Final velocity of object 1:

v₁ = (m₁ - m₂)u₁/(m₁ +m₂)

Final velocity of object 2:

v₂ = (2 m₁ u₁)/(m₁+m₂) =

• Objects do not stick together in elastic collision. They stick together in inelastic collision.

• One object may be stationary before the elastic collision.

Thus, conditions for an elastic collision:

• Energy is conserved.
• Velocities may change.
• Momentum is conserved.
• Kinetic energy is conserved.
• One object may be stationary before the elastic collision.