Chapter 8, Problem 31A

Brian tries to jump from his canoe to the dock. He lands in the water, delighting his companions. What’s your explanation for his mishap?

To determine

To explain: The reason behind the mishap.

Explanation of Solution

Introduction:

As per the law of conservation of momentum, the total momentum of the two objects before collision and after collision will be same in an isolated system.

When a person jumps, then there will be momentum. The momentum of person B and boat will be zero initially. After jump, the momentum will be equal and opposite for both according to law of conservation of momentum when person B tries to jump from canoe to dock that is moving away from it. This is because the boat exerts kinetic energy. Thus, the relative speed of the dock will be reduced. Hence person B cannot jump as far as he has expected.

Conclusion:

Therefore, when person B tries to jump from canoe to the dock, canoe moves backwards and person B moves forward, thus falling short of dock.