Lesson: Applying Newton’s Third Law of Motion to Collisions Physics • 9th Grade
In this lesson, we will learn how to apply momentum conservation to find the forces acting on colliding objects and show that these forces obey Newton’s third law of motion.
Sample Question Videos
A bowling ball with a mass of 12.5 kg and a momentum of 25 kg⋅m/s collides for 0.25 s with a stationary bowling pin of mass 7.5 kg. After the collision, the pin moves at 2.5 m/s in the same direction that the ball moved before the collision. The ball slows to a speed of 0.5 m/s.
What is the change of the momentum of the pin?
What is the change of the momentum of the ball?
What is the force applied to the pin?
What is the force applied to the ball?
During a house removal, a wheeled chair with a mass of 43.2 kg and a wheeled desk with a mass of 108 kg collide with each other. Each object applies to the other a force of 180 N and the collision lasts for 0.15 seconds.
What is the magnitude of the momentum change of the chair?
What is the magnitude of the momentum change of the desk?
What is the magnitude of the velocity change of the chair?
What is the magnitude of the velocity change of the desk?
A ball with a mass of 200 g collides with a wall. The impact of the ball on the wall exerts an average force of 7.5 N on the wall for a time of 0.025 s. The ball rebounds from the wall at a horizontal speed of 0.15 m/s. What was the speed of the ball when it hit the wall?