Re: Biomechanics

["James R. Cunningham" <jrccea@bellsouth.net>]

Ralph W. Miller III wrote:

> _ individual with the lungs about 20
> feet (a tad over 6 meters) below the water level?  Can this be put in terms 
> of psi
> (pounds per square inch)?

0.433 psi per foot of depth, so 20 feet would work out to 8.66 psi. The math is 
62.4
pounds per cubic foot divided by 144 square inches per square foot times 20 
feet of
depth.

> Second, it has been stated recently on this list that a fast running 
> _Tyrannosaurus
> rex_ individual (was it 20 meters per second?)

No.

> would trip and fall on its skull
> with the force of a bus impacting a brick wall at approximately 60 mph.  I
> understand such a hypothetical tyrannosaur was calculated to have sustained 
> fatal
> injuries.  My question: is the 60 mph bus analogy apt?

No.  The speed appears to be way too high, and the animal would impact roughly 
tangent
to the surface, not perpendicular to it.  It'd lose a lot of skin, but might 
well not
break anything.

Jim Cunningham