Question

c) A boy weighing 600  is standing on a platform of dimensions 2.5
  0.5
 . What is the pressure in
exerted by the boy in S.I. unit?

Answer 1

Find the weight in SI units: 600 kgf is

$$P=\frac{P_\text{kgf}}{g}·g=600\text{ N}.$$

The area of the platform is

$$A=ab=2.5·0.5=1.25\text{ cm}^2,\text{ or }1.25·10^{-4}\text{ m}^2.$$

The pressure is

$$p=\frac PA=4800·10^3\text{ Pa}.$$