Question

A boy of mass 40kg is standing on loose sand. if the area of his feet is 0..04 m2 . calculate the pressure exerted by the boy on the sand. take g as 10m/s2 .

Answer 1

F =mg
= 40×10=400N
area = 0.04 m2
p=F/A
= 400N / 0.04m2
=10000 pascals

Answer 2

A boy of mass 40kg is standing on loose sand. if the area of his feet is 0..04 m2 .The pressure exerted by the boy on the sand is 10000 Pa. take g as 10m/s2 .

Weight of the boy = Mass of the boy × Acceleration due to gravity

= (40 kg × 10 m/s^2)

= 400N

So, the force exerted by the boy on the sand (F) = Weight of the boy = 400N.

Also, the area of his feet (A) = 0.04 m^2.

We know that, Pressure exerted (P) = Force(F)/Area(A)

= 400/0.04

= 10000 Pa (Pascals)

So, the pressure exerted by the boy is 10000 Pa