How much pressure will man of weight `80kg` f exert on the ground when (i) he is lying and (ii) he is standing on his feet ? Given that the area of the body of the man is `0.6 m^(2)` and that of a foot is `80 cm^(2).`

Explanation

(i) When man is lying P `=(F)/(A)= (80xx9.8)/(0.6)=1.307xx10^(3)N//m^(-2)`
(ii) When man is standing then A = `2 xx 80 cm^(2) = 160 xx 10^(–4) m^(2)`
`P=(80xx9.8)/(160xx10^(-4))=4.9xx10^(4)Nm^(-2)`