# Wright State University Lake Campus/2017-1/Phy1120/log

## Monday 9 January 2017

• I need to fix error in schedule. We decided to have exams on Monday, and also to meet in one long segment MW starting at 10 AM.
• Assignment:
3. Open your private wiki account wsul### and click edit. You will see instructions enclosed in the "hide" tags: <!-- hidden text-->
2. Fill in PHY1120 as instructed when y
4. Create a word document called Enrollment and put it in your dropbox. For now, it should contain only your wsul### (046-056). Also place your noun### password so you won't forget it.
5. Paste this into your Wikiversity user account

[[Wright State University Lake Campus/2017-1/Phy1120]] - links to roster, with all important links at the top.

## 8 February 2017 (UTC)

### w/o crind

• ${\displaystyle P.E.=q\Delta V}$, where E electric field is and ΔV is voltage
• ${\displaystyle \Delta V=Ed\cos \theta =Ed}$ if d and E are parallel. Here d is displacement.

The above formula fails if E is not constant, but over a small distance it does work. Replace Δ by d and use calculus. For a distance, r, from a point charge or a spherically charged sphere:

• ${\displaystyle |dV/dr|=|E|}$ (I used absolute value signs...don't worry about minus signs because they are too complicated to keep track of)
• You might choose to not learn Special:Permalink/1378605 because it is not likely to be on an MCAT. (It teaches vector algebra)
• Project ideas:
1. Neatly solve problems that were not well solved in the answer key
2. Pose and solve problems in the book that look appropriate
3. Explain something for students. (???)

## 20 February 2017 (UTC) Is the osmotic force a "pseudo-force"?

What is the force that drives the molecules through the membrane? This is a misleading question, because there is no real “force” in the physical sense other than the thermal energies all molecules possess. Osmosis is a consequence of simple statistics: the randomly directed motions of a collection of molecules will cause more to leave a region of high concentration than return to it; the escaping tendency of a substance from a phase increases with its concentration in the phase.

The answer is yes and no. Wikipedia does not include osmotic forces in its article on pseudoforces. But search the word pseud in this excerpt] from the Google books search engine. The quote to the right is a good explanation.