Two hockey pucks with mass 0.1 kg slide across the ice and collide. before the collision, puck 1 is going 15 m/s to the east and puck 2 is going 12 m/s to the west. after the collision, puck 2 is going 15 m/s to the east. what is the velocity of puck 1?

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?