W6

Lectures

Additional lectures (from Spring 2020) are linked at the bottom of the page.

• Tue: (pre-lec pdf, post-lec pdf)

• Thu: (pre-lec pdf, post-lec pdf)

Example Videos

From TA Ian Chaffey.

Reminder: TA office hours are on Friday at 1pm, please find the link pinned to the #general channel of our Slack.

Learning Objectives This Week

• Know how to use the ideal gas law. In a given problem: What stays fixed? What is allowed to change?

• Pressure–Volume (pV) diagrams. There are many paths between different states. In the next few weeks, we'll make a big deal about these paths. For now, familiarize yourself with the phrases: quasi-static, isochoric, isobaric, isothermal.

• General ideas about the macroscopic description of matter: moles as a way to count molecules, identification of temperature as a measure of kinetic energy of molecules

• What happens when you dump energy in? Thermal expansion, phase changes.

Things to think about

• You've got one main equation this week, the ideal gas law. Make sure you know how to use it. Note: this isn't derived from anything, it's just a model for nature, so we're not asking where it came from. (Though you may want to think about how one would have guessed it.)

• A great way to make sure you understand the ideal gas law is to understand how other people misunderstand the ideal gas law. In your explainer videos, take some time to talk about the possible pitfalls when solving problems.

Reading Guide

• Chapters 18.1 - 18.3 are the basics. These are likely to be review topics, please feel free to skim them and refer back to them as needed. Don't use up your brain power on these sections.

• Chapters 18.4 - 18.5 are simple examples of energy in materials. Please skip the material on phase diagrams, it's a bit outside the scope of what we want to learn in this class.

• Focus on chapters 18.6 - 18.7. By the end of this week, you'll need to be comfortable using the ideal gas law correctly. In the coming weeks, we'll be using pV diagrams to talk about energy in gases.

• "Student understanding of the ideal gas law, Part I: A macroscopic perspective," by Kautz et al. American Journal of Physics 73, 1055 (2005). This is an excellent resource for what you need to understand for this chapter. Some of this week's explainer videos will come directly from this article. The article even has the answers and potential pitfalls written out, so you may want to check it out. (take that, Chegg.)

  • You have off campus access to it via UCR if you use the VPN. Using the VPN to access e-books and journals behind a paywall is a useful skill to have.

Homework

Quick Survey

Due Wednesday.

• Submission link: Quick Survey #6

Mastering Physics

Due Friday, graded for completion not for correctness. Unlimited retries. Use this to test out your understanding in a penalty-free environment. Please access Mastering Physics through the Pearson portal.

Explainer Videos

Due next Monday. This week you will have two videos; the assignments are below.

• Submission link: Week #6 Explainers

Peer Review

To be assigned Wednesday, due next Monday.

• Submission link: Week #6 peer review of Week #5 Explainers (please submit 4 times, one for each peer review)

• Peer Review Assignments; if a video is missing, please email the reviewee directly. They need to (1) email you the link to their video and (2) submit using this week's submission form. (Note: submitting via the form won't update the peer review assignments.)

Extra Credit

Nothing has come up this week. Please don't try to launch yourself into space to test what happens to the human body in a pure vacuum.

Explainer Video Assignments

This week we'll continue to assign videos by section. This week everyone has assignments from "Student understanding of the ideal gas law, Part I: A macroscopic perspective," by Kautz et al. American Journal of Physics 73, 1055 (2005). You off campus access to it via UCR if you use the VPN. You are encouraged to refer to that paper: it includes a description of the problem, solution, and potential pitfalls. You should say a few words about some of these pitfalls in your videos.

DIS (Sec 003): W 12:00 - 12:50pm

DIS (Sec 005): W: 5:00 - 5:50pm

DIS (Sec 006): F: 8:00 - 8:50am.