Re: [Phys-l] What are your answers for this teacher?

[Bernard Cleyet <bernardcleyet@redshift.com>]

On 2011, Apr 09, , at 12:55, XX wrote:

> One approach you might consider is when you introduce a new relationship have the students figure out what the triangle should look like. I do suggest that you let them use it. You can give then quiz and test questions like this:
>
> Which of the following is a correct equation for volume given density and mass:
>
> 	• M x D
> 	• M/D
> 	• D/M
> 	• D + M

After this I have a better opinion, however, If they use the triangle for the question above , even after creating it, de nuovo, they will lose the practice of thinking proportionally.

bc




On 2011, Apr 09, , at 08:19, Bernard Cleyet wrote:

> Today's first PTSOS post:
>
> My 9th grade physics students were taught a method for solving speed problems in middle school that does not require algebra. The variables are separated in a diagram of a triangle (or a circle). When you cover up the variable you are solving for, the diagram shows you the recipe on how to solve the problem. If you're not familiar with what I'm talking about, here's a link to an example using Ohm's Law: http://www.electronics-tutorials.ws/dccircuits/dcp_2.html

cut