Monday, November 9, 2009 1:48:18 PM
Hansbo, you may like the speed explanation, but the laws of the Universe really don't give a fap what you like.
Let me try this again. The entire tub is spinning at a rate of 1 revolution per day about an axis parallel to the earth`s axis. The component of that spin around the tub`s vertical axis is proportional to the cosine of the latitude.
The angular momentum of one molecule of water relative to the vertical axis of the tub is 2(pi)r m cos(lat)/t, where r is the distance of the molecule from the rotational axis, m is the mass of the water molecule, and t is the period of rotation.
For each molecule of water in the tub, this quantity must remain constant. When you pull the plug, and the water moves toward the drain, the distance r is decreased, and therefore, the time period t must also decrease to keep the entire quantity constant. In other words, the water HAS to increase it rotational speed as it moves toward the center of the tub to keep its angular momentum constant.