The Aspire 10 Test… were do I begin to write about this???? I know, I start by giving our administration, or IT crew, and our students, and I can’t forget my colleagues that proctored the tests today a HUGE SHOUT OUT. They all really deserve it because we had some pretty major technical issues that they handled with amazing patience during the first test. Imagine about 1000 kids working on tests on issued Chromebooks…. see why they deserve this shout out. They had things running really smoothly for the next two tests, so much so that I’m not the least bit concerned about round two that takes place tomorrow… really, not concerned.at.all.
One cool thing about our Aspire schedule is that I only had 3 of my five classes, well that’s not the cool part. The cool part is that each class was a full hour-long vs. our normal 53 minutes. Yeah, I know only 7 minutes, but 7 minutes is seven minutes. Tomorrow I get the other two for 65 minutes.. awe yeaaaaaahhhhhh.
We started the hour by taking an assessment on Coulomb’s Law. Here are the two problems I allowed the students to choose from:
The next installment of the Mr. Wunderlich questions.
This one was edited just a bit from Jones and Childers.
We also had time to start the discussion the develops the concept of the electric field. I start by explaining the we still do not have a name for the slope of our Fel vs. Charge on q2 graph from our Coulomb’s Law experiment. So I just retrace what we do know about the slope (it increases with a bigger q1, and decreases with a bigger ‘d’) We then review how we ended up with Coulomb’s Law: Fel=(kq1q2)/d^2…. and that this is a long-range force. I remind them that we have only looked at one other long range force, the gravitational force. I confess that I did not provide ALL the details at the time we developed our model for the gravitational force.
SIDEBAR: This was from our Fg vs m experiment where the slope equals ‘g’ defined as the gravitational field strength for the earth, with the model being Fg=gm.
I explain that the REAL equation for the gravitational force is called The Universal Law of Gravitation… Fg=(Gm1m2)/d^2. This is how I get to the Universal Law of Gravitation. We stay on the earth so the equation o: Fg= (G* mass of the earth* m2)/(radius of the earth)^2. We play with a few calcs. where I MAKE them use the entire equation over and over and maybe over until someone complains. Then we do another calculation: (G*mass of the earth)/radius of the earth and … boom it equal 9.8N/kg.
Now it is an easy transition to Electric field (for point charge like we had in our experiment) =(kq1)/d^2. This is our unknown slope.
I like this progression. It explains why we get 9.8N/kg in the ‘Fg’ lab; why different planets have different gravitational field strengths; an introduction to the idea of a field. I suppose I could introduce it right away when we do the Fg lab and then maybe the student might recognize the slope of the Fel vs charge graph right away…. hummmmm, I’ll have to write that down for next year.
From here I head into a uniform electric field created by a positive plate and a negative plate to build the concept of electric potential and electric potential difference (slang term = voltage), a Leyden jar, a capacitor and an electrochemical cell. It is a difficult set of days for the students and for me… usually it is most me talking/telling. I just feel that an advanced physics kid that may go on to take more physics needs to be exposed to the electric field and electric potential (instead of just being told voltage is….). I really do not have the strongest background in electrical concepts which why it is also difficult for me.
Unfortunately, this year, the entire discussion gets (even more) glossed over because if I we don’t there will not be much w time left for circuits, a topic that ALL our kids ‘use’ on a daily basis.
General Physics — Did not meet today because of the Aspire Test