[muawiyah]

Only counts for low density stuff. Now you get a really dense nickel-iron meteor, whizzing along at 15,000 mph relative to Earth, and it is NOT GOING TO SLOW DOWN to 286 feet per second as it enters the atmosphere and punches a hole in a car in Australia or New Zealand!

[Bloody Sam Roberts]

Now you get a really dense nickel-iron meteor, whizzing along at 15,000 mph relative to Earth, and it is NOT GOING TO SLOW DOWN to 286 feet per second as it enters the atmosphere

Your talking about deceleration. An object being dropped into water starts at 0 mph and will accelerate as it plunges to the bottom.

I think Rudder's estimation of 400 mph in water is a bit optimistic. Water is 1000 times denser than air and it's unlikely that any object can reach that speed even from from 5 miles up while starting at 0 mph.