PHY100S - The Magic of Physics - Class 4 - Wednesday January 18, 2006

Reminders

• Please bring a soft-lead pencil to class on Monday. Pre-Class Quiz #2 will be given at the beginning of that class.
• The short paper is due in the Drop Box for your tutor by 5PM Monday January 30.

Pre-Class Quiz #1

Pre-Class Quiz #1 has been marked and loaded into STORM. The class average was 78%, which was good but a bit lower than I anticipated. The hardest question was #3, which only 57% of you got correct. I hope you will all do even better on subsequent quizzes.

Five students filled in a student number that does not correspond to anybody enrolled in the course. These numbers are:

996853443 832624814 993439551 994494045 994477539

In addition, one student did not write his/her name or student number on the paper, and also did not fill in the computer-readable form of the student number.

If you have a problem with your mark on this quiz, please contact April Seeley in MP129 between 1:30 and 5:30 PM. This room is on the first floor of the North Wing of McLennan in the South-West corner.

Today's Class

Today, in part because of technical difficulties, we slipped a bit from the timetable in the Syllabus. We finished §4.4 from last time and talked about §5.1 - 5.2. We'll see if we "make up for lost time" or if this slippage means I'll need to revise the syllabus.

John Meynard Keynes (the economist)

"Newton was not the first of the age of reason. He was the last of the magicians, the last of the Babylonians and Sumerians, the last great mind which looked out on the visible and intellectual world with the same eyes as those who began to build our intellectual inheritance rather less than 10,000 years ago."

Flash Animation

We used a Flash animation that you may access by clicking on the blue button; separate window.

Other Class Materials

We asked some questions in class, available via the button. Separate window.

Here are some comments about the questions and your answers:

1. Who is richer? The first set of numbers are the initial answers to the question by the class. After small-group discussion, you almost completely convinced each other of the correct answer: Your friend on the Moon is richer.
2. You are stationary 1000 km above ... I think you should not be expected to automatically know whether or not the acceleration due to gravity 1000 km above the surface of the Earth is about the same as on the surface of the Earth or is much less. Thus, basically all of the class gave a reasonable answer to this question. It turns out that the acceleration due to gravity 1000 km above the surface is 75% or the value at the surface.
3. You are in a spaceship ... 60% of you got this question correct. The rest should think again about this question and the right answer.

Here is today's Journal file in pdf format. Separate window.