50. You know that a sharp knife cuts better than a dull knife. Do you know why this is so? Defend your answer. 51. Which is more likely to hurt: being stepped on by a 100-kg man wearing flat shoes (Area = 100cm2) or being stepped on by a 50-kg woman wearing high heels (Area = 2 cm2)? Hint: p = F/A 52. Which do you suppose exerts more pressure on the grass: a 5000-kg elephant (feet Area 400 cm2) or a 50- kg lady standing on spike heels (heel Area = 4 cm2)? (Which will be more likely to make dents in a linoleum floor?) Approximate a rough calculation for each. 53. Why are persons who are confined to bed less likely to develop bedsores on their bodies if they rest on a waterbed rather than on an ordinary mattress?