Which statement accurately describes a sample of water during parts a and c of the heating curve?

the working equation for the angular size is the product of the physical size and 360 degrees divided by the product of two pi and distance from earth. the minimum size would be 0.559 degrees while the maximum size would be 0.49 degrees. 

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.