Please help with the following mechanical measurements homework question.

Question

The signal, v(t) = 5cos(2πt) is measured with the following sampling periods of, 3/4 second, 1/2
second, 1/8 second, and 1/30 second. Plot 10 seconds of each waveform using the “stairs()”
command in Matlab and discuss the appearance of the discrete signals, as compared to the continuous
signal, in the context of aliasing.

 

Please show matlab code used.

Answer 1

Hey Joe, in the case that you didn't already figure this out, here's my solution to your problem as I understand it:

t1 = [0:0.75:10];
t2 = [0:0.5:10];
t3 = [0:0.125:10];
t4 = [0:1/30:10];

V1 = 5*cos(2*pi*t1);
V2 = 5*cos(2*pi*t2);
V3 = 5*cos(2*pi*t3);
V4 = 5*cos(2*pi*t4);

stairs(V1);
figure;stairs(V2);
figure;stairs(V3);
figure;stairs(V4);

Answer 2

No-one will be able to help you with this here. We can't put a plot in our responses.

If availability of Matlab is an issue, Mathworks has a version online that should be able to make some simple digital system plots.

http://www.mathworks.com/products/matlab-online

 

Cheers!