Tuesday, July 19, 2016

Value of student pre-reading quizzes. II

Following up on my previous post, below are some selected comments I got from students in my thermodynamics class last semester.
A couple (in bold) comment on how the lectures help understand the reading.
But, there is an interesting follow up. Since the students now have their grades I received the student evaluations. Some complained strongly that the lectures were poor/useless because they just repeated what was in the reading. Others complained that I did not answer all the questions they raised in the reading.

I am sure I can do better, but this just highlights to me that it is impossible to keep all students happy.
For some you go too fast, some too slow.
For some you give too much detail, others not enough detail.
For some you follow the book too closely, for others not closely enough.
For some you repeat things too much, for others not enough.

I would really like to go through the derivations and maths in class. It's so much harder to read than it is to see it being written on the board.

Some things are much easier for me to understand after the lectures. The constant K is exponential decay depending on the change of G and inversely to the T. I'll understand Q2 better after the lecture.

The most interesting was definitely the section on the construction of the phase diagrams from the free energy graphs over various temperatures. I've used phase diagrams extensively before, but have never been taught how they are constructed bar experimental measurements of the temperatures at which solidification begins and ends over a range of compositions. It's great to finally see a theory-based, thermodynamic construction that supports the experimental measurements.

The section on the Eutectic point and eutectic phase changes was confusing at first, then really cool and interesting when I understood. This really strikes me as being a useful application of thermodynamics!

I have just studied phase diagrams for solid solutions in MECH2300 so it was nice to get a better look behind the curtain at what gives the phase diagrams their shape. Thanks Gibbs.

I wish I could learn PHYS2020 through Osmosis

I felt that the section on the osmotic pressure and the derivation of the equation was a little bit rushed and difficult to follow. Also, who lead the Israelites through a semipermeable membrane? ......Osmoses. Get it? Cus... Cus... yeah alright... that's all.

I never had any idea diffusion to was just due to a pressure difference. Now that i think about it it maes sense but it never even crossed my mind why this occured other than simply because mixing would increase entropy and the membrane was permeable. This new interpretation of the event is really interesting.

Of all the reading I was very pleased to see a derivation of the Saha eequation and how basic chemical equilibrium equations were able to be applied to other areas of physics. I've seen the equation arise extensively is astrophysics and it was nice to see how such a seemingly complex relation could be derived so simply by applying the versatility of thermodynamics in physics.

I found the derivation of Le Chatlier's principle to be extremely interesting, as we were taught this qualitatively in Year 12 chemistry, and the derivation was easy to follow and made sense and it was nice to see where this actually comes from

Magnets; how do they work? In all seriousness, paramagnetism and ferromagnetism have come up a couple times, yet we've never covered these in lectures.  Would you be able to go over a brief explanation of them and what they have to do with magnetic dipole moment?

I couldn't pull my head around the magnetic phase boundary, something about it threw me and even after reading it several times I still didn't really understand what was going on.