Mass and Weight

Mass and weight are often used interchangeably in everyday conversation. For example, medical records often show our weight in kilograms, but never in the correct units of newtons. In physics, however, there is an important distinction. Weight is the pull of the Earth on an object. It depends on the distance from the center of the Earth. Weight ...

The mass of an object is a measure of the amount of matter it contains and depends on the number of atoms in it.

Its weight is the gravitational force acting on it from a larger object, like the Earth or the Moon, whichever is nearest to it.

As the amount of matter does not change in response to the applied force, the object's mass...