In an inelastic collision, which statement is true?

In an inelastic collision, which statement is true?

• A. Kinetic Energy is conserved
• B. Momentum is conserved
• C. Both Kinetic Energy and Momentum are conserved
• D. Neither Kinetic Energy nor Momentum is conserved

Answer: (B)

In an inelastic collision, momentum is conserved while kinetic energy is not. The collision forces are internal to the system, and if external forces are negligible during the brief impact, the total momentum before equals the total momentum after. But some of the initial kinetic energy is transformed into other forms—deformation of the objects, heat, sound—so the remaining kinetic energy after the collision is reduced. This is why momentum conservation is the true statement, while kinetic energy is not necessarily conserved in inelastic collisions.

In an inelastic collision, momentum is conserved while kinetic energy is not. The collision forces are internal to the system, and if external forces are negligible during the brief impact, the total momentum before equals the total momentum after. But some of the initial kinetic energy is transformed into other forms—deformation of the objects, heat, sound—so the remaining kinetic energy after the collision is reduced. This is why momentum conservation is the true statement, while kinetic energy is not necessarily conserved in inelastic collisions.