Question

Consider the following problem: An object has a density of 3.85 pounds / ft3. Express this density in g/cm3 Which of the following conversion factors would not be useful in solving this problem? O 2.54 cm/1 in O 3ft/1 yard O 12 inches /1 ft O 2.20 pounds/1 kg O 1000 g/1kg

Answer 1

Convert 3.85 pounds/ft^3 to g/cm^3 i) Conversion of 3.85 pounds to g (3.85 pounds) 1/2.20(kg/pounds) times 1000(g/kg) = 1,750 g {1 kg = 2.20 pounds 1000 g = 1 kg 12 inches = 1 ft 2.54 cm = 1 inch used conversion factor (ii) Conversion of ft^3 to cm^3 (ft)^3 = (12)^3 (in)^3/(ft)^3 times (2.54)^3 (cm)^3/(in)^3 = 28,316.84 cm^3 3.85 pounds/(ft)^3 = 1,750 g/28,316.84 cm^3 = 0.0618 g/cm^3 Hence the conversion factor which is not used = 3 ft/1 yard