Saturday, September 26, 2015

CHALLENGE PROBLEM:
Hint: Find a way to express the function below in a better form.

The following equation describes a wave. Units have been omitted, but you may assume that all inputs/outputs are SI.

y(x,t) = 3e(-1x2+-4t2+4xt)

a.) Sketch the wave at t=0, and then find the following properties of this wave:

Height of the crest: ymax = 3 Correct: Your answer is correct. m
and its location (at t=0): x = 0 Correct: Your answer is correct. m

b.) Now unfreeze the wave from t=0 and find:
the wave's speed: 2 Correct: Your answer is correct. m/s
and direction of travel: +x direction Correct: Your answer is correct.

c.) (NOT FOR CREDIT) Show that this wave obeys the wave equation, though it is not a periodic wave.

use the wave equation https://en.wikipedia.org/wiki/Wave_equation

ddx=1/v^2*ddt

take double derivatives and substitute point values, the double derivitave is quite messy. use wolfram alpha to cheat by doing a single derivative, then a second one. dx 3e(-1x2+-4t2+4xt) then a second one. then dt 3e(-1x2+-4t2+4xt) the direction could be found by graphing 3e(-1x2+-4t2+4xt) with various t values as constant, ex t=1,2,3