Modeling Definition and 554 Threads

I'm trying to model the possble average world temperature for any given day of the year, for planets at varying distances from a star and composed of multiple materials in different quantities for an online game I'm helping develop. basically each planet's composition is simplified to land...

This lonely little Forum hasn't seen much traffic, and I suspect it's because most of you don't know exactly what the field of Systems Engineering actually entails. Given the importance of "the systems approach" to modern engineering, I think a tutorial thread is in order. The discussion...

http://news.bbc.co.uk/2/hi/science/nature/3100024.stm

i'm curious as to how one could model the acceleration of a car through the gears. it would have to be a formula for speed i think, and it would depend upon the current rpm, the gear ratio, the torque (and horsepower derived from it), and the circumference of the tire. i'd appreciate any input.