/1/ Homework is assigned on the LON-CAPA web site:

msu.loncapa.org

Log on using your MSU NET ID.

Click on the course PHY 101.

If you need help, go to Room 1248 and ask a teaching assistant (TA) to show you how to use LON-CAPA.

Form study groups with other students in class and work together. /2/ Next week’s class (Thursday, September 5)

When:

8:00 to 10:00 AM

Where:

Room 106 Farrell Hall (microcomputer classroom)

/3/ Lecture notes are posted at www.pa.msu.edu/courses/phy101 .

101 lecture 1

1

PHY 101 – Lecture 1

Math. Techniques

1 - Algebra

2 - Trigonometry

3 – Analytic geometry

4 - Computer simulation

5 – Calculus

Algebra: Use symbols to stand for numbers.

Example

101 lecture 1

2

2 – Trigonometry

We start with right triangles.

Trigonometry Example

But there’s more to it than that. 101 lecture 1

3

3 – Analytic geometry

The ellipse

Use algebra (and calculus) to analyze geometry problems.

Key technique: coordinates

Rene DesCartes

101 lecture 1

4

4 - Computer simulation

Calculate the area and circumference of an ellipse.

Learn to use the computer program

“Mathematica” which is available in the microcomputer labs in Farrell

Hall. (You can’t afford to buy it for your own computer, but MSU has a site license.)

Preliminary. A circle is a special case of an ellipse; the eccentricity is 0. Semi-major axis = Semi-minor axis a = b = radius r.

For simple computer problems, you could use and EXCEL spreadsheet program, or Wolfram Alpha.

But the easiest way is to use

Mathematica.

Everyone knows the formulas for the area and circumference: Area = r2 ; Circumference = 2 r .

As a numerical example, suppose the radius is 1 m.

Then the area is 3.14 m2 and the circumference is

6.28 m.

101 lecture 1

5

Area of an ellipse:

Computer calculation

Ns = 100 or 1000 or 10,000 x = a/Ns

Strip n:

(x, x+ x) = (a*n/Ns , a*(n+1)/Ns)