[Phys-L] Re: A Third law question

[clement at HAL-PC.ORG (John Clement)]

And what evidence is there for this assertion?  Can you show this by pre and
post-testing on either the FCI or FMCE?  I truly doubt it.

Conservation of momentum is weakly connected to forces in the minds of
students.  Indeed getting them to make the connection is fairly difficult.
There are some excellent direct demonstrations of the effect of forces in
the Interactive Lecture Demonstrations by Thornton et al that work fairly
well and show high gain on the FMCE.  Can you demonstrate similar gain by
using conservation of momentum labs?

If you can get similar gain then by all means publish the results so that
others can use the same method.

John M. Clement
Houston, TX


> Let me reiterate what John D. said. Conservation of momentum is the
> best way I know of to get students to understand forces and their
> affects, including N3. It doesn't require fancy equipment to get
> students to accept it, only a few demonstrations and some hands-on
> work by the students. If these are gen-ed students, they really need
> to get that hands-on work, so they will know what to do with their
> students in due course, and why.