Acircus performer is putting together an act that involves lying on a bed of nails without getting hurt. the tip of each nail has a radius of 1 mm and the performer has a mass of 65 kg. a typical human pain threshold for pressure on the skin is about 0.40.4mpa (1\text{mpa} = 10^61mpa=10 6 pa). this is the minimum pressure that causes a sensation of pain. if the performer stepped on a single nail, what pressure would the nail exert on his foot?