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Question:

A solid aluminum sphere has a mass of 82 g Use the density of aluminum to find the radius of the sphere in?

inchessomeone please show me how to figure this out!!

Answer:

Please note that the first answer has the following formula: Volume mass densityThat is not correct! It was probably a typo It should be Volume mass / density or, as I learned it, DMV (as in department of motor vehicles!) Density mass / volume Things you'll need: Density of aluminum 2.7g/cm^3 Density Mass/Volume Volume of a Sphere 4/3 pi r^3 1 in 2.54 cm How to figure it out (please try to do it without looking at the answers first!): First, you need to find the volume of your sphere by using the dm/v formulaFill in what you know, which is the density and mass, then using algebra, solve for volumeSo you'll have: 2.7g/cm^3 82g/V Now solve for VThe grams cancel, leaving you with only cm^3Solving for V gives you V 30.37037 cm^3 Now you can use your volume in your volume of a sphere formulaThis gives you: 30.37037cm^3 4/3 pi r^3 Using algebra again, solve for your radius cubed: 30.37037 / (4/3 pi) r^3 r^3 7.25092 cm^3 Now, take the cubed root of each side (or raise to the 1/3 power) This should give you: r 1.93547cm Finally, convert your cm to inches 1.93 cm 1in/2.54cm 1.93cm/2.54cm So, your radius of the sphere would be: r 0.761997 in Now that you have your answer, make sure you are using the proper amount of significant digits, which in this case would be 2, so, your final answer should be: r 0.76 in You can work backwards to check your answer.

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