Question

A student initially stands on a circular platform that is free to rotate without friction about its center. The student jumps off tangentially, setting the platform spinning. Quantities that are conserved for the student-platform system as the student jumps include with of the following?
I. Angular momentum
II. Linear momentum
III. Kinetic energy

Answer 1

Answer:

I. Angular momentum

Explanation:

As we know that rate of change of angular momentum is  known as torque.

So we can say that

$T=\dfrac{dL}{dT}$

T= Torque

L=Angular momentum

When there is no any toque then T= 0

$T=\dfrac{dL}{dT}$

$\dfrac{dL}{dT}=0$

So we can say that angular momentum is constant.

In the given problem ,the external torque is zero then the angular momentum of the system will be conserved .

The system have some backward reaction force like axle or pivot that is why the kinetic and linear momentum will not be conserved .