The analogy from my physics class long ago was we each hold one end of a broomstick, if I shove the stick, you'll feel the stick move at a delay consistent with the speed of sound (speed of sound in wood, different than air...) yet the stick actually moves physically a good deal slower than the speed of sound when it transmits the force that moves at the speed of sound. If I whack the broomstick you'll feel it vastly sooner than I can hand the entire stick to you. Speed of sound in wood is hundreds of miles per hour, but I can't physically move a wood broomstick faster than several dozen miles per hour.
Bulk material moves slower than forces move... usually. The physics of shock waves and supersonic stuff is interesting.
Bulk material moves slower than forces move... usually. The physics of shock waves and supersonic stuff is interesting.