4. A fireworks rocket is fired vertically upward. At its maximum height of 80.0m, it explodes and breaks into two pieces; one with mass 1.40kg and the other with mass 0.28kg. In the explosion, 860J of chemical energy is converted to kinetic energy of the two fragments. 1. What is the speed of each fragment just after the explosion

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?