A small firecracker of negligible size rests on a horizontal friction-free surface

PHYSICS · Single correct · CBSE · Physics · Laws of Motion · Laws of Motion

Problem

A small firecracker of negligible size rests on a horizontal friction-free surface. When it detonates, it breaks into two fragments that move only along the surface. Which of the following describes the total linear momentum of the two-fragment system immediately after the explosion? (a) Non-zero, because the chemical energy released produces an impulse on the fragments.\text{Non\text{-}zero, because the chemical energy released produces an impulse on the fragments.} (b) Non-zero and directed toward the lighter fragment since it moves faster after the blast.\text{Non\text{-}zero and directed toward the lighter fragment since it moves faster after the blast.} (c) Zero, because the net external force on the system is zero.\text{Zero, because the net external force on the system is zero.} (d) Zero only if the two fragments have equal mass; otherwise the total momentum is non-zero.\text{Zero only if the two fragments have equal mass; otherwise the total momentum is non\text{-}zero.}

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