1. The problem statement, all variables and given/known data Well, i have built this solar car, and the objective is (in my class) is to see who can get there solar car teh fastest in 20 metres (i.e. who can clear teh 20 metres in teh lowest amount of seconds). My motor specs are 23,500rpm 350gm-cm torque, 150mA all at 14.8 volts. My weight on my car is about 250gm. The gear ratio I have is 8:45, so therefore i have 1968.75 gm-cm of force pushing this car. I have bearings on every wheel, so there is hardly any friction (if that helps). Can anyone help me to calculate the force needed to actually move the car 20 metres in 4 seconds, and if I can enhance the with gear ratios? 2. Relevant equations 1 Newton= 1kg second squared (is this relavant?) 3. The attempt at a solution I have tryed to search google to find any such help in formulae's etc. and my tech teacher doesn't now how to calculate this.