...velocity? So I know that, in order to have a net force greater than 0 the acceleration must be greater than 0, and therefore the velocity must be constantly changing.
Most times after its engine starts, a car accelerates from 0. Then when it hits a certain speed the driver will keep the speed constant. Which means that the acceleration is 0, right? But then if it hits a pedestrian walking by, the pedestrian will get hurt (or fly off from where he was) by the force given by the car. This means that the force is not 0, despite the fact that its acceleration is 0.
If this is the case, what's contributing to the net force hitting the pedestrian?
Most times after its engine starts, a car accelerates from 0. Then when it hits a certain speed the driver will keep the speed constant. Which means that the acceleration is 0, right? But then if it hits a pedestrian walking by, the pedestrian will get hurt (or fly off from where he was) by the force given by the car. This means that the force is not 0, despite the fact that its acceleration is 0.
If this is the case, what's contributing to the net force hitting the pedestrian?