Suppose that Paul D. Trigger fires a bullet from a gun. Will the speed of the bullet leaving the muzzle will be the same as the speed of the recoiling gun? Explain.

The speed of the bullet will only be the same if the mass of the bullet is equal to the mass of the gun. This because only their momentum (product of mass and velocity) is conserved; the momentum before the gun and pullet was fired is equal to the momentum of the recoil of the gun and the momentum of the released bullet. The smallest mass receives the highest speed (the bullet) while the larger mass (the gun) receives the lowest speed (speed of recoil).