Ah, I really love the old "arbitarly apply real world physics whenever convenient, then stop using them when it's not convenient anymore, and only on ways it benefits casters". Let me ask you:
-Why would the dragon take extra damage from being moved at mach 10 when a warrior that charges at mach 10 deals the same damage than a warrior moving at normal speed?
-Who says the dragon is composed of particles at all? Things in D&D are explicitly composed of combinations of the four elements (water, fire, earth, air) or even condensed philosophies. Heck, the dragon is already defying physics by spontaneously developing magic abilities and, you know, breathing fire/acid/cold/electricity/whatever out of nowhere.