Chapter 1, Problem 65P

The volume of a sphere is given by $V=\frac{4}{3}\pi r^3$, where r is the sphere’s radius. For solid spheres with the same density—made, for example, from the same material—mass is proportional to volume. The table below lists measures of diameter and mass for different steel balls, (a) Determine a quantity which, when you plot mass against it, should yield a straight line, (b) Make your plot, establish a best-fit line, and determine its slope (which in this case is proportional to the spheres’ density).

Diameter (cm)	0.75	1.00	1.54	2.16	2.54
Mass (g)	1.81	3.95	15.8	38.6	68.2