Mass of the Earth:m ( E ) = 5.972 * 10^27 kgThe rocky planetsimal:V = 4/3 * ( 100,000 m )³ π = 4/3 * 10^15 * 3.14 = 4.1867 *10^15 m³m ( Planetsimal ) = 4.1867 * 10^15 m³ * 3 * 10³ kg/m³ m ( Planetsimal ) = 1.256 * 10^19 kgFinally:5.975 * 10^27 kg : 1.256 * 10^19 kg = 4.7548 * 10^8 Answer : 4.7548 * 10^8 or 475,480,000 planetsimals
