Homework 2

Description

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.

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