What do you want them to know about mass? If you are doing Newton's Big
Three, you might be trying to show them that mass is a resistance to
acceleration. To that end, you might have them slide a pair of different
sized masses back and forth on a cart, or swing a barbell with different
masses.
To build on the idea of mass, you need to give examples of different objects
with the same mass. That is, you need to show that mass and density are
different ideas. I usually use cubes that are different compositions that
are the same size, and vice versa, objects that are different sizes but have
the same mass.
You of course are also interested in the idea that mass has weight from the
force of gravity. I usually use a spring scale to help illustrate the idea
that the weight pulls things down. Further, I usually then ask what would
happen if there were a place where gravity pulled less hard. The scale
wouldn't go down as much, but would the block itself change?
Finally, I use an inertial pendulum to have the students determine that it
is mass rather than weight that determines accelerations.
Marc "Zeke" Kossover
-----Original Message-----
From: Tina Fanetti [mailto:FanettT@QUEST.WITCC.CC.IA.US]
Sent: Monday, September 24, 2001 12:29 PM
To: PHYS-L@lists.nau.edu
Subject: Re: Weight and Mass
Funny,
That is what I told them..they didn't get it
weight =3D the gravitational force on an object due to Earth
mass =3D the quantity of material present in a sample; fundamentally =
related to the number of atoms in the sample
<<