We can't solve this without knowing the density of the sand. We are given with the side of the cube. From this, we can calculate for the volume. However, to end up with units of mass, you have to use the density. From literature, the density of sand is 1,520 kg/m³. The solution is as follows:
Density = Mass/Volume 1,520 = Mass/s³ = Mass/(1.43)³ Mass = 4,444.79 kg
