Jacques and Georgette meet in the middle of a lake while paddling in their canoes. They come to a complete stop and talk for a w
hile. When they are ready to leave, Jacques pushes Georgette's canoe with a force F to separate the two canoes. What is correct to say about the final momentum and kinetic energy of the system if we can neglect any resistance due to the water
The correct answer is the final momentum is zero but the final kinetic energy is positive.
Explanation:
Solution
Given that:
The momentum is zero because momentum is the sum of the mass * velocity for each component. momentum is conserved
The Kinetic energy (KE) is positive because kinetic energy is the total of the 1/2 *mass * velocity^2.
Whereas the velocity can be positive and negative since it is directed (this is what makes the momentum zero because on is positive and one is negative), the velocity squared will always be positive.
Thus adding together two positives will always be a positive number.
