Why heavier aircrafts take longer to slow down in the air?

[Lyman]

hi bye,

I see no libel. I also see an ephemeral chance for truce.

IMO. Thrust is a force that is not contained in the object to which it is applied.

So, to apply the word Thrust to the system under discussion, we look for a separate object, divorced from the airframe, such that it is subject to, and gains from, the force contained in the system.

The Airmass is acted upon, and reacts to, the entry of the aircraft into its separate region. The aircraft imparts energy to the airmass, the airmass reacts, the airplane slows. Accelerating the airmass produces momentum therein, the aircraft accelerates negatively, etc.

As I say, ephemeral. But not wrong, and in the proper spirit, etc.

bye, bye