Here’s a revised reading schedule for the quarter.
Apologies for taking so long to get this to you. If I’d just shifted everything one lecture slot later, you would have done two labs before you’d reached the concepts in lecture.
Adjustments: We will be having a quick lecture (~20 min) on properties of liquid/gas interactions (section 11.4) before the start of lab on 2/20. We will also have a full-length lecture/workshop on entropy and free energy before our lab clean on 3/6.
The IDEAl solution for this week is the first problem of the revision edition of Quiz 11, finding the electrostatic potential energy of three charges at the vertices of an equilateral triangle. If you make quiz revisions, please use the version posted here (and in the program fileshare).
A quick remark on IDEAl solutions. When you write these, each equation should have a brief justification. By this I mean in terms of the physical situation – why a particular law applies, how the geometry of the problem leads to a particular formula, etc. The one thing that is not what I mean by “justification” is a description of the algebra you have done (or will do) in solving the problem. For instance, if I were doing a problem involving a mass vibrating on a spring that asked for the period, and you wrote the formula omega^2 = sqrt(k/m), you should justify it be writing something like “formula for angular frequency of mass on a spring” rather than “I can use this to plug into T=2 pi omega.” True, you may use that formula to eliminate an unknown quantity as you do the algebra, but the reason you can legitimately use the formula is not because it has a variable you want to eliminate, but because it is relevant to the physical situation.
A way of remembering this is to realize that when I look at your solution, the algebra steps you use will be right there in front of me. You have no reason to describe what you are about to do, because I can see what you actually did! So words outlining your algebra work are unnecessary busy work for you to write and for me to read. What I want you to do is focus on identifying how you know, based on the physics of a problem, what equations are applicable, rather than choosing equations based on what symbols appear in them.
As rated by students elsewhere, Problem 10 was rated 4 for difficulty, 5 and 15 are both a 3, and 2, 11, 12, 13 and 17 were rated 2, with the rest deemed a 1.
System-recorded median time to complete problems rated 10 as the longest, then 17, then 5, 11, 12, 15, 16 and 17 (which were all the same)
A representative from the Washington State Opportunity Scholarship will be visiting Wednesday, February 7, 11:30 am to 3:00 pm, with an information table in the CAB, second floor lobby. Flyer with details; this scholarship has a process for Evergreen students re: the GPA requirement.
Wednesday’s quiz is based on a lot of material. To narrow the scope a bit and reflect what we had time to cover in class, I do not plan to ask questions about the net capacitance of various combinations of capacitors connected in series and parallel. I also noticed that on the last couple of questions of the Week 14 homework there were parts that asked about material that was really covered in Ch. 24 (this week’s reading) – basically, any questions about current. I will not expect you to be able to answer questions regarding electric current on this week’s quiz. (The opposite will be true next week, of course!)