A perfect sphere of lead has radius 6 cm, and weighs 1710 grams. What is its density? Give your answer in g/cm^3. [Density = mass/volume]

To find the density, we need to divide mass by volume, and we already know the mass, so must find the volume.  V = 4/3.pi.r^2, and plugging in r=6 gives V = 48.pi, about 150.8 cm^3. The mass is 1710, which we keep in grams as that is what the answer requires.  Density = 1710/48.pi = 11.3 gcm^-3.