LogFAQs > #970442630

Inertia is an inherent property of mass, not something that gravity imparts. That said, in the case you're describing, your inertia is why you would be able to escape the gravitational pull (or at least escape the range where it's significant, since technically gravity has infinite range but the force imparted scales down by the square of the distance) instead of being sucked directly into the planet as soon as the gravity caught you. You might not feel it, since that would be a pretty gradual force, but you still have inertia regardless of what force is acting on you.

Hard_Light posted...

the only reason you feel the effects of speed is because you're going through air, which has mass

You feel speed because of air, but you feel acceleration because of your vestibular system and the fact that everything inside your body isn't rigidly fixed and will try to stay put/continue moving on its own for a brief period after the outside of your body starts moving. That doesn't depend on air (or any other medium), since it's entirely internal.