mass and weight are different, so why does a book say that?
2006-06-22 21:43:07 · 10 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
I think the equation W = m x g (W = weight; m = mass; g = acceleration due to gravity) might address your question.
Stating they are interchangeable might be misleading if the statement is not qualified by your textbook. The qualification is that when we are measuring objects from an earth reference point, for all intents and purposes, the weight of an object is proportional to its content (i.e., mass). In mathematical terms, the assumption would be, W = m * 1.
However, if we are measuring objects in places other than from an earth reference point, then weight and mass are not interchangeable. For example, the force of gravity on the moon is less than on earth. So as an example, the equation for weight on the moon could be, W = m * .5. With this equation, the weight of an object on the moon is less than its weight on the earth. Here is a math example to illustrate:
Object (Mass) = 100 Kg
g(Earth) = 1
g(Moon) = .5
W(Earth) = 100 x 1
= 100 Kg (Object's weight on earth)
W(Moon) = 100 x .5
= 50 Kg (Object's weight on moon)
Wikipedia might explain the notion of interchange between weight and mass better:
http://en.wikipedia.org/wiki/Weight#Weight_and_mass
2006-06-23 10:41:16 · answer #1 · answered by mindful1 3 · 3⤊ 0⤋
Mass is an intrinsic property of matter, independent of its location.
Weight is the effect of a particular gravitation applied to a mass. An object that has the same mass will weigh differently on the moon than if it is on the Earth, for example.
2006-06-23 04:48:14 · answer #2 · answered by bootothead 2 · 0⤊ 0⤋
Possibly because some substances can interchange between gas and solid/liquid like an equilibrium maybe? When its a gas it has weight and when its not it has mass. Im not entirely sure but its a good guess a?
2006-06-23 04:48:13 · answer #3 · answered by King Julian 2 · 0⤊ 0⤋
When someone asks you your weight you tell them your mass. You dont really tell them your weight. That would require you to multiply your mass times the gravitational force constant.
They are just speaking about the fact that we all use them interchangably so it has become acceptable.
This is perfectly fine.Not sloppy at all. Its just sloppy that people arent more accurate with their language, but then again thats not the point of language. Its communication.
2006-06-23 04:58:02 · answer #4 · answered by Richardicus 3 · 0⤊ 0⤋
I agree; it is a sloppy and potentially misleading / confusing statement; unworthy of a good science textbook!
I guess they mean that we can assume that the material is always weighed in a constant gravity field of 1g (is G capialised there? I forget!) Thus, weight will give a good measure of mass, and may pragmatically be taken as "the same as its mass"..... but oooh! too too sloppy an expression!
:-(
2006-06-23 04:48:28 · answer #5 · answered by J_F_(Self Service Science Forum) 4 · 0⤊ 0⤋
that's crazy! They are NOT interchangeable at all. It would say that because one gram of liquid at sea level is both the mass AND the weight of that unit of liquid.....but ONLY at sea level, and even so, NOT for all objects..... If they say that then they are NOT good books.
2006-06-23 04:46:56 · answer #6 · answered by cyanne2ak 7 · 0⤊ 0⤋
how much something weighs is the amount of mass it has. basically a measure of gravity, unlike matter
2006-06-23 04:46:09 · answer #7 · answered by Anonymous · 0⤊ 0⤋
DEFINITELY THEY ARE DIFFERENT. ON THE BASIS OFCOMMON GRAVITY EFFECT ONLY THE VALUES ARE INTERCHANGEABLE.
2006-06-23 05:39:50 · answer #8 · answered by sures 3 · 0⤊ 0⤋
Because in Chemistry, there is no such thing as gravity.
2006-06-23 04:46:33 · answer #9 · answered by rice c 2 · 0⤊ 0⤋
Because they are directly perportional to each other.
2006-06-23 04:47:10 · answer #10 · answered by Radworks 2 · 0⤊ 0⤋