The average density of living matter on earthâs land areas is 0.10 g/cm2 . what mass of living matter in kilograms would occupy an area of 0.125 ha?

Density is a value for mass, such as kg, divided by a value for volume or area. Density is a physical property of a substance that represents the mass of a certain substance per unit volume or unit area. From the problem statement, we are given the density of the living matter in a particular area and the area. To calculate mass, we simply multiply the area to the density. However, we should remember that the units should be homogeneous or the same and if not, we convert.

Mass = density x area
Mass = 0.10 g / cm^2 (0.125 ha) ( 1x10^8 cm^2 / 1 ha )
Mass = 1250000 g or 1250 kg

Stars are born within the clouds of dust and scattered throughout most galaxies. a familiar example of such as a dust cloud is the orion nebula. turbulence deep within these clouds gives rise to knots with sufficient mass that the gas and dust can begin to collapse under its own gravitational attraction. as the cloud collapses, the material at the center begins to heat up. known as a protostar, it is this hot core at the heart of the collapsing cloud that will one day become a star. three-dimensional computer models of star formation predict that the spinning clouds of collapsing gas and dust may break up into two or three blobs; this would explain why the majority the stars in the milky way are paired or in groups of multiple stars.therefor, i would say the answer is: dust and gases contract.i hope this ! < 3