Answer:
The change in the mass of box = 0.01 kg
Volume of air in the polythene bag = Volume of air in the rigid box
Therefore, Volume of air in the box = 0.008 m^3
Now, Density = Mass/ Volume
=> Density = 0.01 / 0.008 = 1.25 Kg / m^3
Step-by-step explanation:
I looked it up