Determine the mass of air in a room with an area of 20 m3 and a height of 3 m, knowing that the air density is 1.2 kg / m3.

Given:

s = 20 square meters – room area;

h = 3 meters – the height of the room;

ro = 1.2 kilograms / cubic meter – air density.

It is required to determine m (kilogram) – the mass of air in the room.

Assuming that the room has the geometric shape of a rectangular parallelepiped, we find its volume:

V = s * h = 20 * 3 = 60 cubic meters.

Then, to determine the mass of air, you must use the following formula:

m = ro * V = 1.2 * 60 = 72 kilograms.

Answer: the mass of air in the room is 72 kilograms.