0

# How many BBs or ball bearings would fill a basketball?

Updated: 9/27/2023

Wiki User

16y ago

The volume of a sphere is (4/3)(Pi)r3. A Basketball is 9.34 inches in diameter, while a BB has a diameter of 0.172 inches, so dividing the volume of a basketball by the volume of a BB, we get [(4/3)(pi) * 4.67^3] / [(4/3) pi * 0.086^3] = 4.673/0.0863 The calculation is left as an excersise to the student. * The above is based upon the assumption that the BBs will occupy the volume of the basketball with 100 percent efficiency. The trouble is, they won't, so the correct answer will be somewhat less than the above calculation predicts. Spheres typically pack with 60-75% efficiency. Since BBs are very small compared to the basketball, the efficiency should be closer to the high side of that range. If you filled the basketball with ping-pong balls instead of BBS, the efficiency would be lower. See more at http://mathworld.wolfram.com/SpherePacking.html or http://www.ics.uci.edu/~eppstein/junkyard/spherepack.html. * This sounds like it could become a really interesting problem, because you would have to deal not only with the BB-to-BB packing issues, but also how efficiently they stack against the curved wall. A non-regular packing might turn out to be more efficient than a regular one. And what of the manufacturing tolerances on the BBs? If you were looking for a master's thesis topic, you might have found one.

Wiki User

16y ago