Relative velocity of foam chunk?
DrSyn, Could you explain further the 330m/s you give as the relative velocity of the chunk that came off the ET.
I would expect the relative value to be somewhere between the shuttle velocity and zero depending on how long it would take the chunk to accelerate to its falling velocity.
Drag and the thin air density at that altitude would be factors in this acceleration and I don't have the mathematics to work this one out.