Which situation most clearly presents an example of Newton's third law of motion? \[ \begin{array}{ll}\text { a } \quad \text { A rock continues to pick up speed as it falls from a cliff high above the ground. } \\ \text { a 20-kilogram box requires more force to move than a 10-kilogram box. } \\ \text { d baseball breaks a bat by exerting an equal and opposite force when they collide. } \\ \text { A book resting on a table remains in the same position until it is moved by some external force. }\end{array} \]

When a baseball collides with a bat and breaks it, the two exert equal and opposite forces on each other. This classic demonstration of Newton's third law shows that for every action, there is an equal and opposite reaction, making the interaction between the bat and baseball a perfect example of this principle in action. To visualize this concept further, think of how a rocket launches into space. As it expels gas downwards, the equal and opposite reaction propels the rocket upwards! This fun scenario illustrates not only how forces interact but also how they can lead to incredible feats of engineering, like space travel.