Here is a problem I have been developing. Maybe somebody can tell me if it can be solved or if more information is needed.

Three solid balls of radii a, b, and c are placed in a bowl whose inner surface is a hemisphere of radius d. The following information is known:

1) a < b < c < d,

2) d is large enough so that each ball touches a point on the inner surface of the bowl,

3) a is large enough so that each ball touches the other two balls,

4) the balls are made of the same material so that their weights are proportional to their volumes,

5) the forces that the balls exert on each other and the bowl are directed along the lines determined by their centers.

After the balls come to rest, what is the angle between the plane determined by the centers of the balls and the horizontal in terms of a, b, c, and d ?

Assume the diameters of the balls to be just slightly different. The plane of their centers would be nearly horizontal. Now, assume you replace one ball with a much smaller ball which just fits beneath the other two. The plane of their centers then becomes vertical.

 

 

 

 

 

 

Posted by CeeAnne on 2005-09-18 15:18:55