Question $15.(3$ pts$)$ A certain device was made by casting and machining $6\mathrm{.}46$ kg of plutonium alloy into the shape of a sphere. The alloy has a density of $15\mathrm{.}6$ g $/$ cm$3$

$.$ What is the diameter of the sphere if the sphere is solid?

Hint: use algebra to find r as a function of V$,$ then implement your expression in python.