Newtons Second Law is how acceleration of an object depends on both the mass of the object and the force applied. The equation is F=mxa which is F=force, m=mass, and a=acceleration. If you use more force the acceleration goes up and if you use more mass but the force stay the same the acceleration goes down.
An object in motion stay in motion and object at rest stay at rest until an unbalanced forces acts on it.
That the acceleration of the object depends cause with more mass or less or forces applied.
That for every action there is an equal and opposite reaction.
Tendency for an object to resist a change in motion. The more mass an object has, the more inertia.