Question

If a room has dimensions $3m\times 4m\times 5m$, what is the mass of air in the room if density of air at NTP is $1.3kg{m}^{-3}?$

Answer 1

Given, volume of room
$3m\times 4m\times 5m$
$=60m^3$
Density of air at NTP
$=1.3kg{m}^{-3}$
Mass of air in the room
$=volume\times density$
$=60m^3\times 1.3kg{m}^{-3}$
$=78kg.$