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## Homework Statement

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/cm

^{3}

Density of Copper = P(cu) = 8.96 g/cm

^{3}

Volume of Aluminum Cube = Vcube = 729 cm

^{3}

## Homework Equations

Volume of a Sphere = 4/3pi(r

^{3}) - Note: We are solving for 2r (i.e. the diameter).

Density = Mass/Volume

## The Attempt at a Solution

1) Find the mass of the aluminum cube.

Density = Mass/Volume - substitute in known values

2.70g/cm

^{3}= mass/729cm

^{3}

Mass = 1968.3 grams

2) Find the volume of the sphere.

Density = Mass/Volume

8.96 g/cm

^{3}= 1968.3g/Volume

Volume = 219.676 cm

^{3}

3) Find the radius of the sphere.

Volume of a Sphere = 4/3pi(r

^{3}) - substitute in known values

219.676 = 4/3pi(r

^{3})

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.