the weight W of a steel ball bearing varies directly with the cube of the bearing's radius r according to the formula W= 4/3 pi(p)(r)^3, where p is the density of the steel. The surface area of a...

the weight W of a steel ball bearing varies directly with the cube of the bearing's radius r according to the formula W= 4/3 pi(p)(r)^3, where p is the density of the steel.  The surface area of a bearing varies directly as the square of its radius because A =  4 pi(r^2)

a. Express the weight W of a bearing in terms of its surface area

b. Express the bearing's surface area A in terms of its weight.

c. For steel, p = 7.85 g/cm^3. What s the surface area of a bearing weighing 0.62 g?