Conceptual Question 8.09osama wadi

Part A
In a perfectly ELASTIC collision between two perfectly rigid objects
the momentum of each object is conserved.
both the momentum and the kinetic energy of the system are conserved.
the kinetic energy of the system is conserved, but the momentum of the system is not conserved.
the kinetic energy of each object is conserved.
the momentum of the system is conserved but the kinetic energy of the system is not conserved.

Question

Conceptual Question 8.09osama wadi

Part A
In a perfectly ELASTIC collision between two perfectly rigid objects
	 the momentum of each object is conserved.
	 both the momentum and the kinetic energy of the system are conserved.
	 the kinetic energy of the system is conserved, but the momentum of the system is not conserved.
	 the kinetic energy of each object is conserved.
	 the momentum of the system is conserved but the kinetic energy of the system is not conserved.

anonymous · Answer

If the collision is perfectly elastic, then the kinetic energy is completely conserved. Momentum is ALWAYS conserved in any collision, no matter the type.