An area of #"1 hectare"# was filled to a depth of #0.1*m#, and then filled with soil whose density was #1*g*cm^-3#. What mass of soil was used?
We must measure the volume of the plot of the land, and then multiply by the density:
We multiply this value by the depth, to give a volume:
And we multiply this volume by the density to get the mass:
I think this is right (all care taken, but no responsibility admitted!). It is always too easy to make an error in these sorts of calculations. We required a mass, and got a mass. Anyway, please check the calculation. Again, I suspect that the actual density of soil would be much more than