text: if force=mass x accleration than how do you get each one into numbers you can multiply together? for example a car weighs 2500 lbs and is traveling 65 mph how do you figure out its force the example you gave doesn't have enough information to compute the force on the wheels.  in a frictionless world, there would be zero force if the car is traveling at a constant speed on level ground.  in order to compute the force you need to know the resistance to forward motion which is the force due to air resistance, and the rolling friction of the car.  j