Volume of a sphere is:
V = (4/3) × pi × r^3
with pi = 3.141592653589793
Or, just use this online calculator:
http://www.basic-mathematics.com/volume-of-a-sphere-calculator.html
The figure I’ve seen most was a 15 meter diameter. Whether that’s when it exploded, or when it 1st entered the atmosphere, I am unsure. It might have burned off quite a bit of material before it exploded. Nonetheless, assuming a roughly spherical shape, and a 15 meter diameter:
Ice is around 917 kg / cubic meter (varies slightly depending on how cold it is and how it formed), so I came up with around 1600 metric tons assuming the whole thing was ice.
Granite would be around 2700 kg / cu. meter, which gives a mass of roughly 4711 metric tons.
Iron is 7870 kg / cu. m, so that’d run it up to 13,747 metric tons. Now we’re talkin’...
Somewhere in there, 10,000 tons is not an unreasonable estimate, but might be a bit high, as this was likely a “stony” meteorite, I’ve read.
If this had been a fairly solid chunk of nickel-iron, and had not come in at a shallow angle, somebody would not be there any more. Maybe a lot of somebodies.
The AP article on Fox Online was quoting a figure of 10 tons along with the 15 meter diameter. I assume the density of their own brain cells was their reference. (If you are smart and you don’t know, you ask!)
Alert Mayor Bloomberg. Earth is being bombarded with styrofoam meteors! lol
“Journalists” are notoriously inept at mathematics. Or any of the hard sciences and disciplines which require logic.