SAT Subject Physics Practice Question 457: Answer and Explanation
An amusement park ride called DaVinci's cradle swings the riders around a complete circle during the course of the ride.
Where on the ride are the PE and the KE equal to each other?
A. Point A
B. Point B
C. Point C
D. Point D
E. Point E
Correct Answer: C
The correct answer is (C). The cradle is mid-way between its highest potential energy at E and the lowest potential energy at A. Likewise, the cradle is at the point midway between its largest kinetic energy at point A and its least kinetic energy at point E.