The earth's gravity keeps the moon in orbit by pulling on it, the moons gravity pulls back on the earth pushes the moon away from the earth doesn't affect anything can only pull on smaller objects such as asteroids but has no affect on earth

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?