# Circular Motion problem

• irvine752
In summary, a Downy ball is a spherical shell with a diameter of d that is rotating with constant angular velocity in a clothes washing machine. The ball follows a circular path and does not rotate in a plane perpendicular to the angular momentum vector. It is filled with a fluid of uniform density ρ and contains one small air bubble at atmospheric pressure. The question asks about the position of the bubble, initially located directly above the center of the sphere, after the washing machine starts spinning. The answer will involve the variables d and R, as well as constants like the density of the fluid and atmospheric pressure.

## Homework Statement

A Downy ball which can be modeled as a sealed, spherical shell of diameter d is rotating with constant angular velocity in a clothes washing machine. Assume that the Downy ball is confined circular path that undergoes no rotations in a plane perpendicular to the angular momentum vector. The sphere is nearly filled with a fluid having uniform densityρ, and also contains one small bubble of air at atmospheric pressure. Your answer should be a function of variables and constants. Assume that the diameter of the sphere is d and the radius of motion is R.
a)The bubble has an initial position directly above the center of the sphere. Where is the bubble, relative to its original position, after the washing machine starts to spin? (Is it closer to the center of the washing machine or further away)

P = Po + DVh

## The Attempt at a Solution

Honestly, I'm not quite sure how to set up this problem. I need help.

What the heck is a Downey Ball, and how does it move in the dryer and in this question specifically? Is it a ball that is pulled part-way up the cylinder of the dryer by the rotation of the cylinder? And what is meant by the "center of the dryer"? Does that mean the axis of rotation of the dryer drum, or the left-right position of the horizontal center of the dryer?