That is how fast the explosion travels away from C-4 after it is detonated. We watched a 4 lb. device that had galvanized nuts taped to it. Here is a small sampling of what is left of the nuts after they fly 26,400 and go through clothing, wood etc...
We also saw 4 pipe bombs made out of smokeless and black powder and encased in Galvanized and PVC pipe. There were two Ammonium Nitrate mixtures to watch as well. FUN FUN FUN!