Velocity of WTC 1 Roof
Velocity of Balzac-Vitry building in France
Acceleration of WTC 1 Roof
Acceleration of Balzac-Vitry building in France
There is no deceleration in the WTC 1 acceleration graph, only greater or lesser acceleration. However, in the Balzac-Vitry building demolition acceleration graph there is real deceleration at 1.5 seconds into the fall. The velocity in freefall after 1.5 seconds is 48.3 ft./s, so average velocity would have been 24.15 ft./s during this interval. At that average velocity the roof of the Balzac-Vitry building would have fallen 36.2 ft., which is the height of three stories. There were three stories taken out for this demolition which is obvious from the video. This puts the start of the deceleration right at the impact of the upper intact block with the lower intact block.