Can someone tell me how to change a volume in cubic feet to the equivalent area in a sphere? For example-- 3,204 cubic feet would be a sphere of what size?

Question

anonymous · Answer

Volume of Sphere = 4/3 pi r^3
So, find r using your volume.

anonymous · Answer

Err, how do I find radius from cubic feet?

anonymous · Answer

Basically what I'm trying to find out is, If I need 3,204 cubic feet of helium to lift 200 lbs., how do I translate that into a sphere's (balloon's) area so I can figure out the dimensions of the balloon.

hero · Answer

The derivative of Volume in a Sphere is The Surface Area of the Sphere. 

If you know the formulas for both, all you have to do is find the value of the radius, and substitute that into the formula for surface area of a sphere. Do you know the formula for both?

anonymous · Answer

I can google them... Thank you for your answer. I'll try that!

anonymous · Answer

4/3 pi r³ = 3204
=>     r   = ³√( 3204 *3/4π)
Replace into surface area:
SA = 4 π [ ³√( 3204 *3/4π) ]²
Just plug into your calculator!