In an isolated system, the total linear momentum
Correct answer: B. is conserved, whatever type of collision occurs
- A. always increases
- B. is conserved, whatever type of collision occurs
- C. is conserved only in elastic collisions
- D. is zero
Explanation
Momentum conservation follows from Newton's third law and holds in every collision and explosion provided no external force acts, whether the collision is elastic or not. Kinetic energy, by contrast, is conserved only in a perfectly elastic collision. This distinction is what most collision questions are really testing.
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About Collisions
Collisions involve the conservation of linear momentum when bodies interact for a short time. The topic covers impulse, elastic and inelastic collisions, kinetic energy changes, and the coefficient of restitution, with calculations usually based on one dimensional motion. Momentum remains conserved in isolated collisions, but kinetic energy is conserved only in elastic collisions.
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