ENDY 6013 - ENVIRONMENTAL DYNAMICS

HOMEWORK ASSIGNMENT #6a - POTTY TRAINING

DUE FRIDAY, 8 OCTOBER 2004

1. We have discussed the Coriolis "force" as it relates to atmospheric circulation. We also discussed the erroneous view that the Coriolis force affects the motion of water in toilets, causing it to spin one direction in the northern hemisphere and the other direction in the southern hemisphere. A well-done exposition on this topic can be found on the WWW at http://www.ems.psu.edu/~fraser/Bad/BadCoriolis.html.

The Coriolis force can be described in the rotating Earth reference frame by the equation below:

F = 2mvw(sin q)

where F is the Coriolis force, m = mass of air (or water), v = velocity of air (or water), w = angular velocity of earth (expressed in radians per second) and Q = latitude (in radians). Assume the commodes in Ozark Hall are perfectly circular with a radius of 0.33 meters. The latitude of Ozark Hall is approximately 36^o 05' N. Assume the mass of water in each commode is 4 kg and that upon flusing it achieves a velocity of 50 cm s^-1.

Calculate the difference is Coriolis across each commode. Note that you will need to convert all terms to like units (i.e. the final value of F should be expressed in kg radians s^-1). Do you think this is a large or small difference? Do you think it is sufficient to have an effect on water movement in a toilet?

For comparison, calculate the magnitude of the Coriolis Force in 10-degree increments from the equator to the North Pole. Where is the Coriolis Force most pronounced? Where is it weakest?