Hi ruderruderrat,
Originally Posted by
rudderrudderrat
Hi airtren,
Originally Posted by airtren
With no vertical component, there is no height gained/lost, and no potential energy change, or exchange.
We are not considering ballistics.
Aeroplanes convert P.E. to K.E. on every descent by simply using the wings.
An airplane descent implies a speed spacial vector that has a vertical component (vertical speed component), and so the Ep to Ek conversion takes place. And that is true in general with any descent, involving airplanes and wings or not.
If the airplane flies flat, horizontally, the vertical speed component is NULL, and there is no Ep change/exchange. An Ep to/from Ek conversion starts as soon as there is a non-NULL vertical speed component (up, or down) of the speed vector.