# PHY138Y - Mechanics - Class 7- Monday Sept. 29, 2003

## Introduction

"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.”

John Maynard Keynes (1963)

## Getting Into and Out Of Convocation Hall

We are proposing a convention with BIO150 (which meets just before us) and SOC101 (which meets just after us on Wednesdays):

## How Many Problems Should You Solve?

As we say repeatedly, the heart of learning Physics is in solving problems. Thus, the more problems you solve the better. You might consider:

For problems with full solutions, don't peek! Looking at the solutions to problems you have not attempted to solve is unlikely to teach you anything.

When you get a problem wrong, then unless you made a trivial mathematics mistake it is likely that there are one or more concepts which you don't yet fully understand. Thus, doing problems is a diagnostic test of your understanding.

## Problem Set #4

 You may access the problem set by clicking on the button to the right. It is due by 5PM Monday October 6 in the "Drop Boxes" in the basement of McLennan. The file is in pdf format, with a size of 10k.

## Today's Class

We finished Chapter 4. The discussion followed the text fairly closely, except that we extended the analysis of the text's Example 4.5 to similar situations; this extension is extended again in this week's Problem Set.

We discussed §5.2 - Newton's Second Law Applied to a Particle in Uniform Circular Motion, §5.6 - The Fundamental Forces of Nature, and §5.7 - The Gravitational Field.

We then began Chapter 6 - Energy and Energy Transfer. We demonstrated some concepts using "air pucks" which are similar to air hockey games and also to the Air Table experiment in the lab. The Guide Sheet for this non-core second-term experiment, in pdf format, is: