If a ball at the end of a string is whirled in a vertical circle at constant speed, the tension will be
A) the same throughout the motion.
B) greatest at the highest point in the motion.
C) greatest at the lowest point in the motion.
D) greatest at a point where the string is instantaneously parallel to the ground.

Question

Quizplus · Accepted Answer

At the highest point in the motion, the tension in the string must be sufficiently large to provide the necessary centripetal force to keep the ball moving in its circular path. At the lowest point in the motion, the tension in the string must be large enough to provide the centripetal force as well as counteract gravity pulling the ball down. Therefore, the tension is greatest at the lowest point in the motion.

If a Ball at the End of a String Is