Fun and Games
Types of Force
The Force Be With You!
|Weight is a measure expressing the heaviness of an object or
substance as determined by the measurement of its gravitational pull or gravity when placed on a
balance beam or spring scale. As a physical property resulting from the downward pull exerted
on an object by gravity, weight is therefore different from the mass of the object which refers
simply to the quantity of matter the object contains.
Weight and mass are mistakenly compared or considered similar by most people. Weight is the
gravitational attraction between an object and the earth (or some other body). Mass does not
vary, at least not under ordinary circumstances, but weight does, depending on where the
object is. For example, because the Moon is less massive than the Earth, the force of attraction
between the Moon and a person on it is less than the force of attraction between the Earth
and the same person on it. In other words, the person weighs less on the moon. The mass remains
the same, assuming that the person has not grown fatter or thinner during the journey from one
place to another. The mass of an object is the same anywhere in the universe, but the weight
of the object may vary, depending upon the force of the local gravity acting upon it, and
other influences, such as centrifugal force. Any object in free orbit will be in a condition of
weightlessness or zero gravity.