How fast really is 1/8000 shutter speed

I was talking on twitter about a 1/8000 sec shutter speed and this made me think how to even comprehend this. 

Lets put into perspective what 1/8000 shutter speed really means - 

1 / 8000 = 0.000125sec.

400MPH x 5280 = 2,112,000 feet-per-hour / 3600 = 587 feet-per-second

587 * 0.000125 = 0.073ft =0.88 inches

So, a 400MPH object will travel approx. 0.9 inches during the time the shutter is open.

Now what is 0.9 inches of movement - a lot if u r trying to capture a bullet in flight but not much if you are planning to capture a shot of an airplane in flight.