Question

Two students are discussing the motion of the dart-block system at the instant it reaches height H. The

students make the following statements:

Student 1: The speed of the system at height H is zero. Since it is moving in circular motion and

centripetal acceleration is given by , the acceleration must also be zero.

Student 2: The acceleration of the system at height H can’t be zero, or the system would not swing

Answer 1

A:

Student 1 is incorrect. The speed of the system at height H is not zero. Student 2 is correct that the acceleration of the system at height H can't be zero, or the system would not swing.