Question

(a) A boy weighs 50 N. The area of contact of his two feet is 10 cm? What pressure does he exert on the ground if he stands on one foot?(b) A man weighs 250 N. Suppose he stands on a pointed edge with base area 5 cm?. How much pressure does he exert on the ground?(c) Now compare (i) and (ii) to find out the following.(i) Who exerts more force on the ground, the boy in (i) or the man in (ii)?(ii) Who exerts greater pressure on the ground, the boy or the man?(iii) Who is likely to sink into the ground, the man standing on a pointed edge or the boystanding on one foot and why?​

Answer 1

Answer:

a) 10cm² for 2 feets

5cm² for 1 feet

= 0.0005m²

P = F/A = 10N / 0.0005

P = 2000 pa

b) Area = 5cm² = 0.0005m²

Pressure = 250/0.0005

=500000 pa

c) The man who weighs 250N exerts more fore and pressure on the ground. Then man will sink easily because he is standing on a pointed edge