Instructions
You need to use MATLAB for the following problems. When you submit your assignment for grading, please include your MATLAB code. I reccomend using either latex or markdown to create a single PDF file that is easy for us to grade. We will not grade homework that is difficult to decipher.
Problem 1
Consider a simple electric circuit consisting of a resistor, a capacitor, and an inductor as shown below.
The charge on the capacitor q(t) as a function of time can be computed as
q(t) = q0e−Rt/(2L)cos[
s
LC
− ( 2L) t]
1
R 2
where t=time, q0 the initial charge, R=the resistance, L=inductance, and
• =capacitance.
1. Use MATLAB to generate a plot of this function from t = 0 to 0.8 given that q0 = 10, R = 60, L = 9, and C = 0.00005. Be sure to label your axis appropriately for full credit.
2. Using the subplot function, create another plot showing what happens when the capacitor is 10x greater (C = 0.0005). When you turn in your homework, you only need to show the subplot.
3. Explain why the response changed when the capacitance went up.
1
Problem 2
Here are some data for concentration (c) versus time (t) for the photodegradation of aqueous bromine:
t, min
c, ppm
10
3.4
20
2.6
30
1.6
40
1.3
50 1.0
60 0.5
These data can be described by the following function:
• = 4.84e−0.034t
Use MATLAB to create a plot displaying both the data (using red diamond shaped) and the function (using a green, dashed line). Plot the function for t=0 to 70min. Be sure to include a legend and label axis appropriately.
2
