Fermi Estimate: Tennis Balls Packed Inside a Passenger Airliner

Estimate how many tennis balls would fit inside an airplane. Talk through your assumptions and your arithmetic as you go. ```hint Break the plane into simple shapes Approximate the interior with a few shapes you can measure, then think about how much of that space loose round balls can really occupy. ``` ### Clarifying Questions - What kind of aircraft: a single-aisle airliner, a wide-body jet, a small private plane or a cargo freighter? - Is the plane empty but with its seats and fittings still installed, or stripped down to the bare shell? - Should the count include the cargo hold and the cockpit, or only the passenger cabin? - How precise should the answer be: an order of magnitude, or within a factor of two? ### What a Strong Answer Covers - Scoping the aircraft type and which spaces count before calculating - A clear equation linking usable interior volume, ball volume and packing efficiency - Round, labeled assumptions for cabin dimensions, ball size and the space lost to seats and fittings - Correct arithmetic carried through to one number plus a plausible range - A sanity check from a different angle and a view of which assumption moves the answer most ### Follow-up Questions - How would your estimate change for a large twin-aisle aircraft? - Which single assumption has the biggest effect on your answer, and how would you narrow it down? - Could the plane actually take off with all those balls on board?