F7.10 The flame spread rate through porous solids increases with … Read More...
Work is done on a system with the only result of increasing the PE of the system. If 5.24 kJ of work are done, what is the change in PE of the system? Express your answer in units of BTUs. (REPORT your answer to 2 decimal places)

Work is done on a system with the only result of increasing the PE of the system. If 5.24 kJ of work are done, what is the change in PE of the system? Express your answer in units of BTUs. (REPORT your answer to 2 decimal places)

MAE 384. Advanced Mathematical Methods for Engineers. The army is interested in characterizing the acoustic signature of a helicopter. The following data show measurements of acoustic pressure (made dimensionless) for a two-bladed helicopter rotor through 1 2 of a rotor revolution. The data points are equally spaced in time, and the period of the data collection is 1 6 of a second. p0 = [ 0 0.0004 0.0015 0.0028 0.0040 0.0048 0.0057 0.0071 0.0095 0.0134 . . . 0.0185 0.0242 0.0302 0.0364 0.0447 0.0577 0.0776 0.0955 0.0907 -0.0477 . . . -0.0812 -0.0563 -0.0329 -0.0127 0.0032 0.0147 0.0221 0.0256 0.0255 0.0222 . . . 0.0170 0.0112 0.0064 0.0035 0.0023 0.0020 0.0019 0.0016 0.0009 0.0002 ] (a) Find the real Discrete Fourier Transform for this data set. That is, nd the Fourier coe¢ cients (the Aks and Bks). (b) Any term in the Fourier series can be written: Ak cos(k!t) + Bk sin(k!t) = Ck cos(k!t + k) where Ck = q A2 k + B2 k and k = tan?1 ?Bk Ak Find the Cks and plot their amplitude vs. k to illustrate the relative size of each term in the series. (The amplitude should drop of with increasing k.) (c) Plot the function (Fourier series) and the original data on the same plot. (d) The actual loudness of the helicopter depends on the maximum peak-to-peak amplitude of the signal. Find the peak-to-peak amplitude by nding the maximum and minimum values of p0 as predicted by the Fourier series solution. Recall that a function has a maximum or a minimum when its derivative equals zero. (e) Extra Credit. Try nding Aks and Bks for k > N 2 (where N = the number of data points). Show that the resulting series does not represent the data.

MAE 384. Advanced Mathematical Methods for Engineers. The army is interested in characterizing the acoustic signature of a helicopter. The following data show measurements of acoustic pressure (made dimensionless) for a two-bladed helicopter rotor through 1 2 of a rotor revolution. The data points are equally spaced in time, and the period of the data collection is 1 6 of a second. p0 = [ 0 0.0004 0.0015 0.0028 0.0040 0.0048 0.0057 0.0071 0.0095 0.0134 . . . 0.0185 0.0242 0.0302 0.0364 0.0447 0.0577 0.0776 0.0955 0.0907 -0.0477 . . . -0.0812 -0.0563 -0.0329 -0.0127 0.0032 0.0147 0.0221 0.0256 0.0255 0.0222 . . . 0.0170 0.0112 0.0064 0.0035 0.0023 0.0020 0.0019 0.0016 0.0009 0.0002 ] (a) Find the real Discrete Fourier Transform for this data set. That is, nd the Fourier coe¢ cients (the Aks and Bks). (b) Any term in the Fourier series can be written: Ak cos(k!t) + Bk sin(k!t) = Ck cos(k!t + k) where Ck = q A2 k + B2 k and k = tan?1 ?Bk Ak Find the Cks and plot their amplitude vs. k to illustrate the relative size of each term in the series. (The amplitude should drop of with increasing k.) (c) Plot the function (Fourier series) and the original data on the same plot. (d) The actual loudness of the helicopter depends on the maximum peak-to-peak amplitude of the signal. Find the peak-to-peak amplitude by nding the maximum and minimum values of p0 as predicted by the Fourier series solution. Recall that a function has a maximum or a minimum when its derivative equals zero. (e) Extra Credit. Try nding Aks and Bks for k > N 2 (where N = the number of data points). Show that the resulting series does not represent the data.

clear all; clc; period = 1/6; p = [0       0.0004 … Read More...
A catalyst can increase the rate of a reaction __________. A) by changing the value of the frequency factor (A) B) by increasing the overall activation energy (Ea) of the reaction C) by lowering the activation energy of the reverse reaction D) by providing an alternative pathway with a lower activation energy E) All of these are ways that a catalyst might act to increase the rate of reaction

A catalyst can increase the rate of a reaction __________. A) by changing the value of the frequency factor (A) B) by increasing the overall activation energy (Ea) of the reaction C) by lowering the activation energy of the reverse reaction D) by providing an alternative pathway with a lower activation energy E) All of these are ways that a catalyst might act to increase the rate of reaction

D) by providing an alternative pathway with a lower activation … Read More...