Re: kinetic energy paradox?

["RAUBER, JOEL" <JOEL_RAUBER@SDSTATE.EDU>]

> Is the answer just that Earth receives MANY such impulses
> continuously, one right after the other, and each impulse is
> *instantaneously perpendicular to the displacement (and
> velocity) vector at that same instant*? And it's the
> *tangential* speed that determines the orbital kinetic
> energy, and this component isn't changed.

Essentially yes, what's different about the other case?

Your impulse is necessarily over a time interval and during part of that
interval the impulsive force will have a component partially in the
direction of motion.

(if you consider an instantaneous impulse, you'll have an arbitrarily large,
infinite, acceleration, due to an infinite force; which we may consider as
being unphysical in this context.)