Leigh might have a point... the intent of this question might be clear...
because a person who understands the full range of responses would probably
conclude B is the answer a physicist would expect.
But I don't think John Mallinckrodt is out in left field. Suppose you're
trying to push something into the ground, or you're using a drill, etc. and
someone says "put your whole weight into it." Isn't it clear that they are
viewing your weight as the force you exert on the object? I remember my
daughter being angry at her brother and telling me, "He stepped on my hand
on purpose, and he put his whole weight on it." Gosh, I think I told a
student just a few days ago, you need to push down pretty hard, but don't
put your whole weight on it or you might break it." Shame on me.
The point... this is another case where common everyday language might be at
odds with physics language (or maybe not, from John's point of view). So I
think we have to be careful how we word things (what's new?). A quick look
at some of the physics books on my shelf show that it is not unusual to
refer to the contact force an object exerts on its support is its weight.
If a book is sitting on a table, and we draw the free body diagram of the
table, we might initially draw the force of the book on the table as F(T,B)
(force on the table due to the book). But in the words we use to describe
that force, we are likely to say that F(T,B) is the weight of the book on
the table. Perhaps some of you would never say this. But I hear it, and I
see it in some physics books.
Michael D. Edmiston, Ph.D. Phone/voice-mail: 419-358-3270
Professor of Chemistry & Physics FAX: 419-358-3323
Chairman, Science Department E-Mail edmiston@bluffton.edu
Bluffton College
280 West College Avenue
Bluffton, OH 45817