- #1

sodnaz

## Homework Statement

A 0.50kg puck rests on a level air table and is connected by a light thread passing through a hole in the table to support a hanging mass of 3.0 kg. A stable orbit is achieved when the puck is sent into a circular path of radius 0.15 metres around the hole.

(A) neglecting friction at the edge of the hole, calculate the period of revolution of the puck in its orbit.

## Homework Equations

Centripetal force = Tension - Weight

V=2πr/T

## The Attempt at a Solution

I know that at that position, F = T-W

I saw this solution online:

However, I don't get why Fnet (centripetal force) = 0 in this instance? If the puck is in it's orbit, how can the centripetal force be 0? Can you explain that please? I just don't understand why the centripetal force is 0?

Thanks