Hi At the risk of upsetting the predominance of Americans on the list can I suggest using kilometres per hour or metres per second (metres/sec would be best) for your calculations? Also better to use kilograms for weight, millimetres for linear measurements. If we ever want research students to pick up on our pets and help us help the fuzzies we'd be better off to use the internationally accepted system of measurement. Just my 2c worth :) Rob -------------------------------------------------------------------- Rob Dick, Adelaide, Australia. [log in to unmask] URL: http://www.RKT-Weblife.com.au "We make our world significant by the courage of our questions and by the depth of our answers." Carl Sagan, 'Cosmos', 1980. [Posted in FML issue 2101]