Answer to Question #168720 in Mechanics | Relativity for Stephen

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

The tension in the string provide the net force, Centripetal force is provided by the weight of the object.

Thus the claim that sphere can have a centripetal force without any individualforce pointing toward the center of its circular path.

When we talk about the acceleration in circular motion since The velocity is equal to 0 so the acceleration i.e. the rate of change of velocity must be 0.