RE: Biomechanics

[Toby White <augwhite@neosoft.com>]

On Tuesday, September 07, 1999 5:33 AM, John Clavin 
[SMTP:jclavin@microsoft.com] wrote:

[snip]

> This sounds a little far fetched. To start with 20m/s is a too quick for a T
> Rex. It works out at 72km/hr or 45 mph. Perhaps 15m/s is more realistic
> (about 33-35 mph). Also most buses weigh a lot more that a Tyrannosaur. If
> we assume that our T Rex is about 2 metric tonnes - sprinting at 15m/s into
> a brick wall will have a collision force of about 30 kiloNewtons.
> If it tripped up and simply fell on the ground, all that force would be used
> up in skidding to a halt on it's chest or side. Lots of scrapes, but I can't
> see it being fatal.

Depends how it landed and what the surface was.  The bus/brick wall is the 
upper limit.  Not many brick walls in the Cretaceous.  Then again, it probably 
wasn't landing on Nerf, either.

> As a final thought - how could a creature have been successful if it had a
> significant risk of death every time it sprinted after it's dinner?
> "Nature" doesn't design things that badly.

Maybe because it didn't sprint after its dinner.

  --Toby White