Hello all, The company that I work for was involved in a soapbox competition over the weekend. During the design of the car, the consensus was that adding more weight inside the car (without affecting the shape) was a good thing. With more mass, the racer would have more momentum, so when the force of air resistance acted against it, the relative change in momentum would be less than for a lighter vehicle. Anyways, we didn't make it to the finals, so now people are saying we should have made the car lighter, since adding more weight increases the amount of friction (neglecting air resistance). The analogy made was that four wheels roll down a hill are faster than four wheels on a car in neutral rolling down a hill. Personally, I'm not too sure about this one, because the air resistance on a car and the air resistance on four wheels is different. What about four heavier wheels vs. four lighter wheels both of the same dimensions on a windy day? So what do you guys think? Is heavier better? I'm inclined to think that there is a happy medium - some amount of weight that doesn't increase the rolling friction too much but gives the car enough momentum so that it won't be stopped by a strong gust of wind. Thanks!