Last week, major news outlets reported that the inner core of Earth was about to stop turning. Now a prominent columnist has declared that the Chinese balloon weighed as much as three buses, which is about 105,000 lbs. This is baloney. So I did a calculation.
We need the diameter of the balloon. Based on a photo, and the length of the truss, stated by U.S. authorities as three coach bus lengths (12 meters/bus X 3), the diameter is estimated as 50 meters.. We use:
- Density of helium at STP.
- Height of 20,000 meters.
- An altitude air density table for standard day,
- Adjustment of buoyancy for altitude with Boyle’s Law.
- F=m*g for the force to be balanced.
This determines a total weight in the vicinity of 11,000 pounds. The payload may be a third of that.