Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: A weighty subject



On Fri, 15 Oct 1999, Joel Rauber wrote:

I'm convinced to ignore things like buoyancy in the definition. But in the
elevator accelerating upwards, in the frame of reference of the elevator,
there is an inertial force upwards as well as a normal force upwards on the
object being weighed on the scale.

No. From the Newtonian viewpoint, there is an inertial force downwards
that adds to the gravitational force making the normal force larger.

Do you really want to call that inertial force a part of the
gravitational force.

With the correction above, yes, I do. But for my introductory students
no. I would stop at saying that the object's weight is equal to the
magnitude of the normal force, e.g., m(g+a).

John Mallinckrodt mailto:ajm@csupomona.edu
Cal Poly Pomona http://www.csupomona.edu/~ajm