I'm dealing with a small toy car consisting of a bottle that has a small hole in the back, covered by a thumb tack. The bottle is filled with pressurized air then the thumb tack is released, releasing a stream of air that acts as a thrust force to propel the car. I am trying to determine its acceleration and force of friction.
I cannot find an equation to determine rolling friction! I do not need an explicit one necessarily, ex. it could be one that could be used to determine it indirectly. Example: If there's an equation that can be used to determine acceleration other than the traditional forces approach (ex. here; I actually thought I had it made with this one, but its derivation for acceleration is on a slope assuming only friction and gravity.) that would enable me to determine net force, then subtract the force of thrust (I've calculated it already) to find the force of friction.