Roughly how many ping pong balls would it take to fill a school bus?

To estimate how many ping pong balls fit in a standard school bus, we can use a basic volume calculation:

1. Volume of a school bus: A standard full-size school bus has an interior volume of roughly 250 to 300 cubic feet. Let's use 275 cubic feet as a reasonable average.
2. Volume of a ping pong ball: A regulation ping pong ball has a diameter of 40mm (about 1.57 inches). Using the formula for the volume of a sphere, one ball is about 2.03 cubic inches.
3. Packing efficiency: Because spheres cannot pack perfectly without empty space, we must account for "packing fraction." For randomly poured spheres, you typically fill about 60-64% of the space with the balls themselves, while the rest is air.

The Calculation:

• Convert the bus volume to cubic inches: 275 cubic feet × 1,728 (inches per cubic foot) = 475,200 cubic inches.
• Account for packing efficiency (approx. 62%): 475,200 × 0.62 = 294,624 cubic inches available for balls.
• Divide by the volume of one ball: 294,624 / 2.03 ≈ 145,135.

Accounting for seats, the driver's area, and wheel wells, you would likely lose about 20-25% of that usable space. Adjusting for that, you would need roughly 110,000 to 120,000 ping pong balls.

Keep in mind this is an estimate based on averages; the exact number would fluctuate depending on the specific model of the bus and how tightly the balls are packed.