1. The problem statement, all variables and given/known data What is the diameter of a copper sphere that has the same mass as a 9.00 cm× 9.00 cm× 9.00 cm cube of aluminum? Density of Aluminum = P(al) = 2.70g/cm3 Density of Copper = P(cu) = 8.96 g/cm3 Volume of Aluminum Cube = Vcube = 729 cm3 2. Relevant equations Volume of a Sphere = 4/3pi(r3) - Note: We are solving for 2r (i.e. the diameter). Density = Mass/Volume 3. The attempt at a solution 1) Find the mass of the aluminum cube. Density = Mass/Volume - substitute in known values 2.70g/cm3 = mass/729cm3 Mass = 1968.3 grams 2) Find the volume of the sphere. Density = Mass/Volume 8.96 g/cm3 = 1968.3g/Volume Volume = 219.676 cm3 3) Find the radius of the sphere. Volume of a Sphere = 4/3pi(r3) - substitute in known values 219.676 = 4/3pi(r3) Radius = 52.4438 cm Diameter = Radius * 2 = 104.8877 cm Everything looks pretty spot on to me; however, my online homework says this is incorrect. Any help would be greatly appreciated. Thanks guys, Justin Daniels. P.S. This is my first post. Please let me know if I've failed to follow the format for posting questions, so I can correct this moving forward.