Kaplan 10th Edition DT Q73

Kaplan's Book

73) Problem 73 asks us to consider the answer choices and choose the true choice. We are given the situation of a ball in a vertical circular motion.

All of these answer choices consider the tension force at each of the three points. In order to consider the tension, we need to take a look at the centripetal force.

Where F[c] is centripetal force, m is mass, v is velocity, r is radius, and F[Net] is the net force

Since F[c] is also F[net] in the central direction, we can equate F[c] to the sum of the forces in the central direction.

Where F[g] is gravitational force, T is tension force, and F[c] is centripetal force

Finally, we need to create equations for each point and compare.

Where F[g] is gravitational force, T is tension force, and F[c] is centripetal force

Looking at these equations, I can glean that the tension is greatest at point 3, but least at point 1. This is described by answer choice A.

Answer: A