Mission NL1 Inertia and Newton's First Law
Different forces are applied to objects of varying mass. The resulting accelerations are shown. Rank these objects ...
Inertia is the property of an object which describes its natural tendency to keep on doing whatever it is doing.
Not all objects have the same amount of inertia. Some objects have more than others. That is why inertia is sometimes described as a property of an object. Such a property cannot depend how the object is moving - whether it is at rest, gradually accelerating or rapidly accelerating. Consider this analogy: color is a property of your car. If your car is red, then the color red describes an intrinsic property of your car. If your car was red when at rest, green when accelerating gradually and yellow when peeling out, then red would not be an appropriate property to describe your car. In the same sense, inertia is a property of an object. And being a property of an object, the inertia of the object cannot be different at low accelerations than at high acceleration values. Inertia depends solely upon mass - which for our purposes, is that unchangeable quantity which describes how much stuff an object possesses. In this sense, inertia - or mass - is an intrinsic property of an object.
