Dimensional Analysis Problem Help

Question

The average density of the earth is 5.52 g/cm3, what is its density in (a) kg/m3 and (b) lb/ft3?

Answer 1

Dimensional analysis: set up so the units you don't want cancel, and you are left with the units you do want.

5.52 g/cm³ x 1 kg/10³ g x 1cm³/10^-6 m³ = 5.52 x10³ kg/m³

Do the same using 454 g = 1 lb and 1 cm³ = 3.5x10-5 ft³