Makeshift office hours today.

For today, I will be holding informal office hours in the lecture hall for two hours before lecture begins. SO… from about 11:30 AM until lecture, you can check in and work on HW with me or any other topic.

Homework 9 is ready.

You can now work on homework HW 9. It mainly concerns interference effects, but there is a bit of wavelngth practice in there, too.

We have an important demonstration tomorrow.

Make every effort to be in lecture tomorrow, Feb. 19. We will have a demonstration of diffraction.

It is important because it will be the backbone for a huge amount of physics, starting in this chapter on waves, next unit on electricity and magnetism, then on to the periodic table, chemical compounds, rocks and minerals and oceanography -- i.e., the remainder of the semester!

HW 7 is UP.

Homework #7 is now available. For extra safety, I set it so that you can make five attempts.

As always, read carefully!

Revised S.I. schedule, plus review for Exam 2.

Here is the revised S.I. schedule:

Day	Time	Room
Monday	10:30-11:20 AM	CB1 309
Wednesday	9:00 AM – 9:50 AM	BHC 129
Thursday	4:30 PM – 5:20 PM	ENG2 105
Friday	11:00-11:50 AM	CB1 109

Don't forget: Lacey's review session prior to Exam 2 is Monday, Feb. 10, 4:30-6:30 PM in CB1 307. Even if you can only make it for twenty minutes of those two hours, you go! It is worth it!

Your iClicker data are now up to date.

I just finished uploading i>Clicker2 data from lecture L5 on Jan. 15 up to yesterday's lecture L11.

Pay no attention to the percentages etc. in the grey area below the i>Clicker2 data. Those percentages are inaccurate but cannot be turned off.

Homework 5 is ready.

There is a new homework assignment, HW 5, ready in Webcourses. It includes some practice with computing stopping time and stopping distance.

Remember: Webcourses rewrites the calculation problems with random values of speed, mass etc. each time you attempt the homework.  So you cannot recycle answers from one attempt to another.  Read carefully!