6 Flags Magic Mountain Field Trip is Tuesday, May 28. Attending this trip is optional.

 

Students, to get cleared by your parents to go on this trip, you must direct them to this site:

 

 

where they will take action to clear you.

 

Students, once your parents have cleared you, to go on the trip, you must bring me the F-602 Form and payment (check payable to PVHS) together no later than Wednesday, May 22. The cost will be $85*. I will only accept the complete F-602 Form and the payment at the same time.

 

The trip is not officially happening until there are enough students to fill at least one bus. (Two are ordered.) If not enough students sign up to go, both buses get cancelled on May 22, and the checks are all returned to students/families to be destroyed. If there are enough students for one bus but not two, then one bus will be cancelled. Suppose the bus can only take 50 students, but 70 students get cleared, hand in their forms, and hand in their payment. In such an event, 50 students will go, and the other 20 will not. The 50 who go will be determined by First-Come-First-Served Priority. Priority for attending the trip will be given to the first 50 who got cleared (via the link above), handed in the F-602, and handed in the payment. This means that when students hand in the F-602 and check, I will put a number on the form with lowest number meaning earliest handed in. F-602 forms are available as hard copy directly from Mr. Warren and there is also an electronic version on the link above. (But the copy directly from Mr. Warren is preferable, because of information he wrote on it.)

 

*The $85 figure was arrived at from a calculated budget that I will share in class. For the trip to come in just under budget (meaning it will not be cancelled) there needs to be a minimum of 48 students signed up to go. (At 48 students, the projected cost comes out to $84.80 per student.)

 

The attachment repeats the problem and has a brief and thorough key. Also, I had an arithmetic problem on the board and said one answer came out to square root of 46 m/s. The actual answer to that was the square root of 49.7 m/s. The physics and algebra were fine; just an arithmetic error. It's correct on the attachment.

 

And see the other posting about the Magic Mountain details. I handed out the F-602 form in class. The trip cost is $85. Please don't wait to tell me you're coming and get form and payment in. I'll be out of town on Thursday May 16 and Friday May 17, so tell me sooner than May 15.

 

As part of AP Review, topic inventories... You do them, right?

 

The attached ones (one document, two semesters) are thorough. See if they help.

Score Calculation on the Final:

 

Overall score is not Multiple Choice Score + Raw Free Response score.

 

It's Multiple Choice Score + (0.66666667 times Raw Free Response score).

 

This is consistent with what I told the class when I handed out the final. I said the Free Response would be scored with a 15-point rubric to determine the raw score but then scaled down to only be worth 10 of the 45 point test points. 35 points Multiple Choice, 10 points FR. The raw score written on the free response page is what the students earned of 15. For example, this means a 9 of 15 scales to 6 out of 10. So if a person earned 25 multiple choice points and the rubric yielded 9 of 15 as the raw free response score, the overall score would be calculated as:

 

25 + 6 = 31, and 31 would be the final overall score.

 

If a person wanted the free response points to be counted as the raw score in the test total, it means the final goes up to 50 points total (35 multiple choice and 15 free response.)  If I were to do that (aside from it not matching what I said ahead of time I would do) it would raise the cutoffs for 3's, 4's, and 5's. The cutoffs were 51 of 90 (56.67%) for a 5, 40 of 90 for a 4 (44.44%) and 33 of 90 for a 3 (36.67%). So if the test were out of 50, the cutoff point values would be 29, 23, and 19, based on those percentages.

 

The scale just mentioned was for a test given nationwide where students had 90 minutes to do the same multiple choice plus three free responses. In my class, students had that multiple choice test and only had to do one free response and were given 105 minutes.

 

You have the keys for these for 84, 88, 93, and 98 over where I posted the bunch of E&M MC tests.

 

The pdf is the FULL booklet for the 2012 exam. You don't need to print out the whole booklet. You can scroll to the MC test and then find its key toward the end of the booklet. I've just been informed that this 2012 one exists for E&M as well. I've attached that here too. To be used sometime between 5/2 and 5/11 if anyone wants to.

 

You've seen the same form 3 times, with the same patterns repeating over and over. It's time to take advantage of that. Attached. Very brief.

Two Important Keys to Some Classwork Notes. The idea is to only need page 2 of the attachment called "Numerical Inductor Intro Circuit Problem". Page 1 was to have already been processed before today, and the new Page 2 is for checking the answer and the main idea.

 

As for "Three Graphs of Current Versus Time": this is the key and the discussion for the single-page that I gave anew on Friday 4/26. To do this task independently and without my help, ONLY use Page 1. If you get it wrong, go to the other pages for concept-checking. It presumes that you have already done "Numerical Inductor Intro Circuit Problem" and have already completed Unit VIII workbook through Page 19.

 

Aside from that, I said, "Finish everything" and use the practice tests I've provided so steadily review for the final. As of Thursday, April 26, I have completed all 8 units of the workbook. So you finish them too, plus problems at the end of the unit.

 

I also announced that the final on Thursday, May 2 will be a multiple choice test with 1 Free Response Problem, and the free response problem will be on Unit VIII.

 

1) Work toward completing Unit VIII ASAP. (It won't all get done in two days.)

2) Open the attachment to this message. There see all 8 experimental scenarios, two of which you were graded on, in class on Monday, April 22. On paper, do the 6 you weren't assigned to do in class, and redo the ones you were assigned to do if you know you did them incorrectly. See below the list of potential weaknesses (coded A, B, C, and D) which could have a affected a person's performance on this. (I do believe there are only 4 possible ways that a weakness could impact a person.) On graded student papers, I wrote any applicable letters A, B, C, D, on the graded paper as a code to tell a student where he/she was weak in relation to those 4 areas (if applicable.)

3) After doing or redoing the 8 tasks, check the key.

4) After checking the key, link what's in the key to the central idea in Unit VIII named Lenz's Law. When all is said and done, a flawless answering of all 8 scenarios begins to amount to what one could call the lab-based discovery of Lenz's Law.

 

An important difference between the attachment and the papers used in class: To make the scenarios answerable at home, any ammeters in the diagrams for situations 1, 2, 3, and 8 now include the location of the red wire port and the black wire port, exactly as they were set up in class. This information was not included in the in-class paper to answer for credit, because you're supposed to know that you were expected to observe those red and black locations for yourself. It was not my responsibility to tell you where the black and the red of the ammeters were located. By working as an independent observer and from being reminded that you might need to get up and look at the apparatus to answer the question, it should be expected by you that your observations were part of the lab grade. Situations 1, 2, 3, and 8 are impossible to answer if one doesn't see how the red and black of the ammeter are connected to the secondary coil, and I was never going to say "Now don't forget to go see where the red and black are connected."  I did notice that some people who had those stations to answer did not seem go get up and look. (Maybe I'm wrong; maybe they could see the colors from across the room. Decide for yourself what was required for you to see, and know that everything was available with flawless matching between diagrams and apparatus. And everything worked correctly.) If a student neglected to see how the black and red ports of the ammeters were connected, this could signify weakness D that I list below.

 

So in the attachment, to make them worthwhile practice problems at home, I added the info on how the red and black ports were plugged in AND I added the actually way that ammeter needles deflected. This will enable you to pretend you were here seeing those with your eyes.

 

Weaknesses that could have affected performance on this specifically are lack of certainty with the following skills:

 

A. Basic vector directions, and distinguishing a vector's direction from the direction of that vector's change and factoring into this distinction whether the vector is strengthening or weakening.

B. Correctly associating the direction of a circular source of current and the direction of the B field that that source causes*.

C. Basic definitional knowledge of B's direction to begin with.

D. Ability to successfully observe the direction of current either through meter behavior or via magnetic force evidence.

 

*Example: If a person in one place said that CCW current causes an interior B field that's dot and in another place said that CCW current causes an interior B field that's x, then it might be a struggle for that paper to earn a B, if this assessment is supposed to measure basic Unit VII knowledge.

 

Clarification: In class, at 2:45, I understated the number of people eligible for A's when I listed off a series of names, and it's good for you to know why. I based that initial filtering of the papers on whether people always had deltaB opposite to B-induced in their final answers. (You'll find out why this matters.) I at first used this criterion to see who could get an A, because I know what final answers I'm looking for (through Lenz's Law.). But at the time, I also knew that I'd be looking more carefully and possibly broadening the A category, because since nobody had to know about Lenz's Law before coming into this, a person could have a minor mistake that causes one directional reversal, and that alone could be the source of why Lenz's Law appears violated in the final answer. As of 4/22, I'm not expecting that anyone would use Lenz's Law to check a final answer; I'm just saying that I WAS using it to give me a quick key at first. Now, my 4-lettered list of important strengths and weaknesses above is the more thorough grading tool, and that's what I used in the end. So here's an example:

 

A person was given scenarios 1 and 8 to analyze. (I recommend you open the attachment to follow along with this carefully.) It's important for you to know that I made sure that everybody got one scenario with a strengthening primary B field and one with a weakening primary B field. This student said "dot followed by x" in the first two entries in scenario 1's chart and "0 followed by dot" in the first two entries of scenario 8's chart. This means the person has no weakness in topic A above. (I also would have accepted "dot then dot" for the first two entries in scenario 8.) But the student had a final answer that violated Lenz's Law, so I knew there was an error somewhere, and where was it? So next I looked at his last two entries: I-induced compared to B-induced, and there I saw no problems whatsoever with skill B above - his clockwise current always went with x caused by it in the middle of the solenoid. Then I looked at skill C. The fact that the student said the original B fields caused by the primary sources were all in the proper direction told me there was no weakness with skill C. So the only possible weakness was in current-meter observation, and he got one of the two of these current-meter observations correct. So the violation of Lenz's Law in this person's final answer has been narrowed down to one bad meter read and only in one of the two scenarios. This paper is a 9/10. Papers with only one weakness are possibly eligible for an A, but it depends on how Unit VII-heavy that weakness was. For example, if the one weakness is skill B above, that invalidates the A-grade, because Skill B is a big one. (Not that this matters, but a large fraction of the class did not show signs of weakness B on 4/22.)