Question

Many people are familiar with the fact that a rifle recoils when fired. This recoil is the result of action-reaction force pairs. A gunpowder explosion creates hot gases that expand outward allowing the rifle to push forward on the bullet. The bullet pushes backwards upon the rifle. The acceleration of the recoiling rifle is

• A. greater than the acceleration of the bullet
• B. smaller than the acceleration of the bullet
• C. the same size as the acceleration of the bullet
• D. None of these

Answer 1

The correct option is B

smaller than the acceleration of the bullet

The force on the rifle equals the force on the bullet. Yet, acceleration depends on both force and mass. The bullet has a greater acceleration due to the fact that it has a smaller mass and hence for the same force the acceleration developed in the gun is less.