Question

If the density of copper is 8.92 g/cm3, what is the mass of a copper BB (sphere) with a diameter of 4.500 mm?

Answer 1

Given the density of copper is -8.92g/cc

We know the formula of density = mass/ volume

Given the diameter of copper sphere = 4.5mm

Then radius = diameter/2 = 0.45mm/2 = 0.225mm

Volume of sphere = 4/3 πr³

therefore volume of copper sphere = 4/3.22/7.(0.225mm)³

=0.0477mm³

We know that 1cc = 1000mm³

Then 0.0477mm³ is how man cc?

= 0.0477×10^-3 cc

By substituting this volume of sphere in the density formula we get the mass of copper ball.

= 8.92 g/cc . 0.0477×10^-3 cc

= 0.43×10^-3g

= 0.43mg

Hence the mass of copper ball is 0.43milli grand.