so if we wanna find the force of a car with a mass of 1500 and going a constant velocity of 14m/s would it just be 0?? but if velocity is constant then A=0 so then force would equal zero too!? how can that be,because if it hits something it obviously exerts a force?? or would you just use the acc of gravity?? Is weight measured in newtons? does weight = force? if a car accelerates 2 m/s^2 and has a mass of 2 kg then its force=4 N right? but what exactly does it mean to have a force of 4N??? does that mean it will take 4N to stop it?? thanks for the help!