Superman leaps in front of Lois Lane to save her from a volley of bullets. In a 1-minute interval, an automatic weapon fires 148 bullets, each of mass 8.0 g, at 350 m/s. The bullets strike his mighty chest, which has an area of 0.72 m2. Find the average force exerted on Superman's chest if the bullets bounce back after an elastic, head-on collision.