Re: Student Questions

[John Barrer <forcejb@YAHOO.COM>]

Start by getting them used to the question "What
objects are interacting with the mass?" Direct contact
means there's a force and for all your situations, the
Earth interacts with the mass. Hold objects, pull
springs, set a 1kg mass on a meter stick supported at
the ends, etc. Identify contact (forces) first, then
ask if the force is a push or a pull. A great demo to
disconect force from motion is to have a hunk of dry
ice. Have them do a force diagram for the stationary
block. Then give the block a push, get theatrical to
show that you're not touching it, and then ask for a
diagram for the block while it's gliding along on the
cushion of CO2 gas. John BArrere
--- Tina Fanetti <FanettT@WITCC.COM> wrote:
> Hi all
> I am currently teaching forces to my general physics
> class.  I ask th=
> em if they are getting what I am doing...
> She says she is confused and she doesn't get it.
>
> How can I question her in a way that helps me see
> why she doesn't get=
>  it
>
> Tina
>
> Tina Fanetti
> Physics Instructor
> Western Iowa Technical Community College
> 4647 Stone Ave
> Sioux City IA 51102
> 712-274-8733 ext 1429


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