There are formulas for regular shapes. Not all shapes have formulas; for these you can fill them with liquid and measure or weigh the contents.
If you are given the volume, then you do not need to work it out!
Tonnes do not measure volume.
No problem. The volume of a gas is the volume of whatever container you're keeping it in.
divide the mass by the volume: mass/volume=density
This can not be worked out as volume is bassically a measure of size and so you need the dimensions to work this out, however if you mean density than you can not work that out without knowing the weight and volume.
Volume: l times w times depth
tidal volume x breathing rate
you dont
Density = (Mass) divided by (Volume) If you know the density and volume, then Mass = (Density) times (Volume)
volume=area of the cross section x the length
Its volume is its cross-section area times its length.
Density is mass divided by volume.