On Fri, 03 Mar 2006 08:00:45 -0800, fredfighter wrote:


Jose wrote:
Suppose we have a 1500 lb airplane in level flight at 120 mph.
What are its horizontal and vertical components of momentum?

Zero at equalibrium.


Suppose we have a 1500 lb rocketship hovering over the moon on its
rocket exhaust. What are its horizontal and vertical componnts of momentum?

Again, zero.



I asked first.

Same answer, different criteria. Net energy for a given mass will be
the same whether the craft is flying, rocketing, or in orbit.

F=MA

But, only in the instance of 'flying' does Bernuolli apply.