Answer:[tex]1.3\times10^{-9}kg[/tex]
Volume of each grain of sand:
[tex]V=\frac{4}{3}\pi r^3[/tex]
radius of the spherical grain is given,[tex]r=49.8\mu m=49.8\times10^{-6} m[/tex]
[tex] \Rightarrow V=\frac{4}{3}\times3.14\times(49.8\times10^{-6})^3m^3=5.17\times10^{-13}m^3[/tex]
The grains are made up of silicon dioxide.
The density is equal to [tex]D=2600 kg/m^3[/tex]
Then, the mass of each grain is given by:
[tex]Mass=Density (D)\times Volume(V)\\ \Rightarrow M=2600 kg/m^3\times5.17\times10^{-13}m^3 =1.3\times10^{-9}kg[/tex]
