On Fri, 03 Mar 2006 17:56:39 +0000, Alan Baker 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.

Incorrect. It has considerable horizontal momentum and no vertical
momentum.

I thought the focus was forces.

The 'aircraft' with respect to the media, air.

If the ground is at play with respect to horizontal 'componet'
is it in the form of 'gravity' (a force) or geologial energy
of some sort expressed as the force of location?

This is hightly interesting. Never thought of it before.