🚀 go-pugleaf

On Tue, 21 Feb 1995 20:18:44 PST John Mallinckrodt said:
>         If you really want to determine the mass of something
>then you'd better apply a known force to it and measure its
>acceleration.  I think I can make a pretty good case that that's
>exactly what a spring scale does and that, therefore, spring
>scales measure mass.
>
Now, John, I am not sure whether you are referring to determining
the inertial mass of an object by producing an acceleration with
a spring scale (which of course must be exerting a net force)
or whether your reference is to determining gravitational mass
by suspending the object from a non-accelerating spring scale --
in which case there is actually no acceleration.  I don't think
it really matters whether you say "mass this object" or "determine
the mass of this object," but students struggle so much with
forces and all of Newton's laws that we should not say weigh
when we mean determine the mass of.

Van, I already know that you think this is a fairly unimportant
issue (i.e. the distinction between mass and weight), but when
kids are trying to make sense of N1,2&3, it really is important
for them to be able to distinguish between the 2.

Van, I'm having a de ja vous (sp?) -- why did you start this?
We've had our annual discussion of net force versus centripetal
force -- I suppose the mass/weight issue was due.  8-)
                                 (smiley face with sunglasses
                                  symbolizes Cherie longing for
                                  springtime & warmth & sun)

Cherie                                 Cherie Lehman
clehman@purccvm.bitnet                 West Lafayette High School
clehman@vm.cc.purdue.edu               West Lafayette  IN  47906
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