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Dec12-08, 12:54 PM
P: 67
because in an elastic collision that repels a bullet, thereby causing it to go back in the oppisite direction with an almost equivalent speed, the kinetic energy must be conserved. if the bullet was stopped and all the kinetic energy was transfered into the steel block, then maybe it could have a greater speed. but to me it doesnt seem very likely. As for an inelastic collision, where the bullet goes into the box, all the kinetic energy of the bullet is being transfered over to the final mass and velocity, the mass of the box plus the mass of the bullet times the final velocity. Therefore, since more kinetic energy is being put into the wooden block, it moves faster, unlike the steel box.