A small firecracker initially at rest on a frictionless horizontal surface explodes…
PHYSICS · Single correct · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
A small firecracker initially at rest on a frictionless horizontal surface explodes into two fragments that slide apart. No external horizontal forces act on the fragments before, during, or immediately after the explosion. Which of the following statements most accurately explains why the total horizontal momentum of the two-fragment system immediately after the explosion is zero?
(a) Because the chemical energy released is converted entirely into kinetic energy, energy conservation requires the momentum to remain zero.
(b) Since the two fragments have equal mass, they recoil with equal and opposite velocities, so their momenta cancel.
(c) The internal explosive forces occur in equal and opposite pairs, so they supply no net impulse to the system.
(d) With the center of mass initially at rest, each fragment must individually end up with zero momentum.