Forces contribute to the net force on a car rolling down a ramp.
a. which force supports the car’s weight?
b. which force accelerates the car down the ramp?
c. which force acts against the motion of the car?

Consider two less-than-desirable options. in the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. in the second option you are driving 30 mph and crash head-on into a stationary brick wall. in neither case does your car bounce off the thing it hits, and the collision time is the same in both cases. which of these two situations would result in the greatest impact force?