How fuel filled, aluminum jet aircraft wings could travel through the WTC steel facade at 500 mph at the weak points (breaking the bolts and welds).
The government’s calculations put the speed of the first plane at 494 mph, and the second at 586 mph. The MIT analysis determined the first plane was traveling 429 mph, and the second 537 mph, The Times said. (source)
E=MC squared (energy=mass • speed squared)
Ken Jenkins on the Pentagon attack: Final approach of the plane accelerated from 300mph to when it hit Pentagon at 561 mph, at about 100 tons. An object going 500 mph is 10 times faster than 50 mph, but has 100 times the energy! (source @ 51:30)
Wayne Coste says the planes broke the WTC steel facade where there were bolts or welds. (source @ 1:09:30)
Sep 27, 2016
Target shots from five of our supersonic ping pong ball launches at the 2016 Portland Oregon OMSI Maker Faire. Ball speeds reached 873 meters/second (1950 MPH) in one of the launches, the fastest ever. This is the first time we’ve successfully broken through nominal 3/4 inch plywood. (The plywood actually measures 17mm, slightly less than a real 3/4 inches, which would be 19mm.)
Increased speed was primarily due to a longer 20′ (6.1 meter) launch tube. See other videos on this channel for details of the launcher.