Re:A First Look at America's Supergun
by dredmorbius on Saturday May 28, 2016 @03:45PM
(#11793107)
The impact of a jumbo jet on a building is relatively modest. Not good to those on the directly affected floors, but even high-speed direct impacts are sustainable.
It's the jet fuel that melts steel beams.
Kinetic energy = 0.5 * m * v^2
The energy density of kerosene (jet fuel) is about 33 MJ/l
We can compare the impacts of American Airlines Flight 11, a Boeing 767-233ER weighing about 180 tonnes, with about 38,000 l of fuel aboard, with the energy capacity of that fuel, comparing both to barrels of oil equivalent, using GNU Units:
You have: 0.5 * (180 tonnes) * (748 kph)^2
You want: barreloil
* 0.63494668
/ 1.5749354
And for the fuel (I'm assuming 1kg/l for kerosene, this is slightly high, but the fuel quantity isn't precisely known. Rough accuracy is sufficient.)
You have: 0.907 * 38 tonoil
You want: barreloil
* 235.81404
/ 0.0042406296
The energy of the plane's fuel is roughly 370x that of its kinetic impact.
It's the jet fuel that melts steel beams.
Kinetic energy = 0.5 * m * v^2
The energy density of kerosene (jet fuel) is about 33 MJ/l
We can compare the impacts of American Airlines Flight 11, a Boeing 767-233ER weighing about 180 tonnes, with about 38,000 l of fuel aboard, with the energy capacity of that fuel, comparing both to barrels of oil equivalent, using GNU Units:
You have: 0.5 * (180 tonnes) * (748 kph)^2 You want: barreloil * 0.63494668 / 1.5749354
And for the fuel (I'm assuming 1kg/l for kerosene, this is slightly high, but the fuel quantity isn't precisely known. Rough accuracy is sufficient.)
You have: 0.907 * 38 tonoil You want: barreloil * 235.81404 / 0.0042406296
The energy of the plane's fuel is roughly 370x that of its kinetic impact.