Question

What are the forces imparted by atmosphere on the walls of a room of dimension $6m\times 5m\times 4m$? ($1$ Atm. = ${10}^{5}N/m^2$).

• A. $7\times {10}^{6}N$
• B. $2\times {10}^{7}N$
• C. $2\times {10}^{8}N$
• D. $2\times {10}^{6}N$

Answer 1

Answer: (D)

$2\times {10}^{6}N$

The atmosphere imparts a force normal to any surface in contact with it. We know that the atmospheric pressure
$=\frac{NormalForce}{Areaofthesurface}$
$⟹P=F/A⟹F=PA$.
The area of the walls of the room are $(6\times 4)m^2$ and $(5\times 4)m^2$ respectively putting $P={10}^{2}N/m^2$ and the area of the walls we obtain $F=2.4\times {10}^{6}N$ and $2\times {10}^{6}N$ respectively.