the effect of inertia on objects at rest
Inertia The term "inertia" was first introduced by Johannes Kepler in his Epitome Astronomiae Copernicanae[22] (published in three parts from 1617â€“1621); however, the meaning of Kepler's term (which he derived from the Latin word for "idleness" or "laziness") was not quite the same as its modern interpretation. Kepler defined inertia only in terms of a resistance to movement, once again based on the presumption that rest was a natural state which did not need explanation. It was not until the later work of Galileo and Newton unified rest and motion in one principle that the term "inertia" could be applied to these concepts as it is today.[citation needed]
Momentum Example: A model airplane of mass 1 kg accelerates from rest to a velocity of 6 m/s due north in 2 s. The net force required to produce this acceleration is 3 newtons due north. The change in momentum is 6 kg⋅m/s. The rate of change of momentum is 3 (kg⋅m/s)/s = 3 N.