Definition:Weight (Physics)/Weigh
Definition
To weigh a body is to determine its weight, and thence its mass.
Similarly we can say that:
- body $B$ weighs $x$
to mean:
and both mean the same thing.
Warning
There is a certain amount of confusion in the common mind between weight and mass.
The latter is usually determined by measuring its weight.
But while the mass of a body is (under normal circumstances) constant, its weight varies according to its position relative to the gravitational field it is in, and so is not a constant property of that body.
However, under usual terrestrial conditions the gravitational field is more or less constant (any differences being detectable only by instruments).
This means that the weight and mass of a body are commonly considered "the same".
Thus a weighing machine, while indicating the mass of a body, does so by measuring its weight.
Sources
- 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): weight
- 2021: Richard Earl and James Nicholson: The Concise Oxford Dictionary of Mathematics (6th ed.) ... (previous) ... (next): weight