In this problem, we want to understand the temperature
component of our environment using Fourier series andlinear system theory. The file
temperature.mat contains these data
(daylight hours in the first row, corresponding averagedaily highs in the second) for Houston, Texas.
Let the length of day serve as the sole input to asystem having an output equal to the average daily
temperature. Examining the plots of input andoutput, would you say that the system is linear or
not? How did you reach you conclusion?
Find the first five terms
(
,
... ,
)
of the complex Fourier series for each signal.Use the following formula that approximates the integral required to find the Fourier coefficients.
What is the harmonic distortion in the two signals?
Exclude
from this calculation.
Because the harmonic distortion is small, let's
concentrate only on the first harmonic. What is thephase shift between input and output signals?
Find the transfer function of the simplest possible
linear model that would describe the data.Characterize and interpret the structure of this
model. In particular, give a physical explanationfor the phase shift.
Predict what the output would be if the model had no
phase shift. Would days be hotter? If so, by howmuch?
Fourier transform pairs
Find the Fourier or inverse Fourier transform of the
following.
Duality in fourier transforms
"Duality" means that the Fourier transform and the inverse Fourier transform are very similar.
Consequently, the waveform
in the time domain and the spectrum
have a Fourier transform and an inverse Fourier transform, respectively, that are very similar.
Calculate the Fourier transform of the signal shown
below .
Calculate the inverse Fourier transform of the spectrum shown
below .
How are these answers related?
What is the general relationship between the Fourier transform of
and the inverse transform of
?
Spectra of pulse sequences
Pulse sequences occur often in digital communication and in other fields as well.
What are their spectral properties?
Calculate the Fourier transform of the single pulse shown
below .
Calculate the Fourier transform of the two-pulse sequence shown
below .
Calculate the Fourier transform for the
ten -pulse sequence shown in
below .
You should look for a general expression that holds for sequences of any length.
Using Matlab, plot the magnitudes of the three spectra.
Describe how the spectra change as the number of repeated pulses increases.
Spectra of digital communication signals
One way to represent bits with signals is shown in
[link] .
If the value of a bit is a “1”, it is represented by a positive pulse of duration
.
If it is a “0”, it is represented by a negative pulse of the same duration.To represent a sequence of bits, the appropriately chosen pulses are placed one after the other.
What is the spectrum of the waveform that represents the alternating bit sequence “...01010101...”?
This signal's bandwidth is defined to be the frequency range over which 90% of the power is contained.
What is this signal's bandwidth?
Suppose the bit sequence becomes “...00110011...”.
Now what is the bandwidth?
Questions & Answers
A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?