Question

The mass of air in a room of dimensions $4.5m\times 3.5m\times 2.5m$ if the density of air at N.T.P. is $1.3kg{m}^{-3}$ is X kg. Find X.

• A. 55
• B. 51.19
• C. 60
• D. 70.19

Answer 1

Answer: (B)

51.19

We know that, $Density=\frac{mass}{volume}$
where volume $=4.5\times 3.5\times 2.5=39.375$
$\Rightarrow mass=density\times volume=1.3\times 39.975=51.19kg$