Question

Volume of a sphere = 4/3πr³ where r is the radius.

Cobalt has a density of 8.861 g/cm³.
How many kilograms would a sphere of cobalt with a radius
of 7 cm weigh?
Give your answer to 1 d.p.

Answer 1

Explanation:

Find the volume of the sphere (in cm^3) then multiply by the density given

4/3 pi r ^3 = 4/3 pi (7^3) = 1436.755 cm^3

1436.755 cm^3 * 8.861 g/cm^3 = 12 731 .09 gm = 12 . 73 kg