No Subject

[David Brian Walton <dbwalton@u.washington.edu>]

Dear AMath 383 class,

Okay, so there is another part of the homework that probably doesn't 
make enough sense yet because of our slight lagging in the lectures. In 
problem 1, part (a), the problem asks to compare the solution to an 
equation in the lecture notes to identify two different characteristic 
velocity scales and a time scale.

First, the equation in the lecture notes is more general than the 
problem for the homework. It includes how to break an initial velocity 
into the horizontal and vertical components. This is why there is the 
presence of sin(theta). The homework problem doesn't deal with the 
horizontal part at all, and so theta=pi/2, where sin(pi/2)=1. So ignore 
the sin(theta).

Then the problem is a matching problem. Find a term that is multiplied 
by an exponential and call that one velocity scale. Find a term that is 
multiplied by 1 minus the same exponential and that is the other 
velocity scale. Find the term in the exponential that divides t, and 
that is the time scale.

We will motivate this type of choice better on Wednesday in class.

Best wishes,

D. Brian Walton
AMath 383 Instructor
Guggenheim 408C
(206) 685-9298