A ball striking a wall head-on and bouncing straight back exerts a force on the wall, and the wall's force on the ball is deduced using:

1. The force on the ball comes from Newton's second law and the ball's momentum change. 2. The force on the wall is then the partner of that force. 3. In order to determine the force on the wall, consider the force on the ball due to the wall using Newton's second law and then apply Newton's third law to determine the direction. 4. The first ball bounces directly into the wall and exerts a force on it in one direction. 5. Therefore the wall exerts a force on the ball in the opposite direction. _Source: OpenStax College Physics for AP(R) Courses 2e (CC BY 4.0), Ch 8 'Linear Momentum and Collisions', sections 8.1-8.7_