How does momentum and inertia affect changes in speed, when considering acceleration from thrust, or from decelleration from drag? Say, for a fixed mass of 100kg, at a velocity of 10m/s, is a force of 10N is applied in the forwards direction, then F = ma -> a = F/m. a = 10/100, a = 0.1 m/s^2. But how does the object's inertia affect this? Or is that dealt with in that equation? Also, if the same object where no longer being forced forwards, how would the air resistance affect the motion of the object when considering its momentum and inertia?