Homework #1
due 9/15/17
1. The first assignment is to fork the course syllabus and assignment.
a. Sign into your UConn github account via github.uconn.edu.
b. Go to https://github.uconn.edu/rcc02007/ME3255F2017.git and watch the repository.
c. Fork the repository to create your own version of the syllabus and assignments.
2. The next assignment is to create your own repository named '01_ME3255_repo'.
a. (if you signed out) Sign into your UConn github account via github.uconn.edu.
b. Follow these steps to create your own repository named 01_ME3255_repo:
i. Click the +-sign and choose 'New repository'
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ii. In the 'Repository name' enter '01_ME3255_repo'. Add a description. Make it private. Then check the box 'Initialize this repository with a README'.
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iii. Now you are in your repo. Click on the README.md file and then click the pencil to edit it.
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iv. Add a header with a # and type # Answer to Homework Question. Under this
line answer this question: What do you hope to learn this semester?
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v. At bottom of page, click 'Commit changes'.
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vi. Verify that your README.md file has been updated. Then copy the HTTPS clone URL on the right of the page.
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vii. Paste this into the Homework #1 Google form reponse. https://goo.gl/forms/b3YrBuFxZaXTYV5s1
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viii. Click on the gear for "Settings" then "Collaborators" on the left menu. Add
rcc02007 (Ryan C. Cooper) and zhs15101 (Zhiqiang Shen) as a collaborators.
3. Use a script to create a variable called A_66, where every element is the product
of the two indices from 1 to 6 e.g. A_66(3,2)=6 and A_66(4,4)=16. Calculate the mean and
standard deviation of the values in A_66.
4. Copy the data in
US_energy_by_sector.csv
to a file in you working directory in Matlab/Octave. Add these two plots to your
01_ME3255_repo with a heading of #Problem 4
a. Plot the US energy consumption from 1949 to 2016 for "Total Energy Consumed by the Residential Sector" and "Total Energy Consumed by the Transportation Sector" in trillions of Btu's.
b. Plot the cumulative US energy consumption from 1949 to 2016 for "Total Energy Consumed by the Residential Sector" and "Total Energy Consumed by the Transportation Sector" in quintillions of Btu's (1 quintillion = 10$^6$ trillion). The cumulative energy is the area under the curve in part a from 1949 to a given year.
5. In this part, you will modify the function presented in lecture freefall.m. In
lecture, the function required an input of N to divide the 12 second solution into
N-steps. Here, modify the input so that you can specify two inputs, step size-h, and
timespan-timespan.
a. Plot a comparison between calculated velocities v(t) for timesteps of h=0.1, 1, and 5 sec from 0 to 30 seconds.
b. Save the script that created the comparison plot as 'freefall_comparison.m' and the
figure as figure01.png (use command > print(figure01.png))
c. Save your work to a folder called 'problem_3' and add it to the '01_ME3255_repo' repository
6. In this part we will create functions that calculate velocity and acceleration in 3D based upon x,y,z-coordinates and time. (hint: look at Lecture 04_intro to m-files
a. Create a function that takes four vectors as input, x,y,z,t,(where x,y,z are coordinate positions in meters) and its output are three vectors [vx,vy,vz] which are velocity components in m/s.
b. Create a function that takes four vectors as input, x,y,z,t,(where x,y,z are coordinate positions in meters) and its output are three aectors [ax,ay,az] which are acceleration components in m/s$^2$.