Class 10 and Discussion 5,  Tuesday, 2/8/05

Highlights of Class 10
Dr. Chau discussed  the material related to the following two chapters of TB1.
* The true meaning of E = m c^2
    ** It contains both the rest mass energy and the kinetic energy in an exact beautiful way.
    ** When (v/c)^2 << 1,  E_0 + E_k .
* The g of the Earth, and other planets, was derived, using Newton's universal law of gravity.
* From the expression of E_p, the potential energy under gravity,  the simple result of the potential energy above the surface of a planet was derive.
* Discussed how to derive the escape velocity, and how to use the expression to convert energies from one form to the other.

Highlights of Discussion 5
Discussed HW6: SA6.1, SA6.2, and SA6.3. Students participated.
* Reviewed how to take square root without using a calculator.
* Hints are given how to calculate g_mar on Mars in the unit of g on Earth, by Dr. Chau's unified method of unit conversion by using 1. And then look up the mass and radius of Mars in terms of those of the Earth in TB2.
* Discussed how to use the expression of energy conservation to convert energies from one form to the other.
(As always, it regretable that some students did not participate in the Discussion. It is designed to help students with the new material and new HW. Students should by all means attend and take advantage of it, to make the learning and doing HW more efficient.)
   


Week-6 (2/6 -2/12)
  · p.432-452, S2 of  TB1: Space and Time;
  · p.453-476, S3 of  TB1 : Spacetime and Gravity.
  · No reading of TB2.