ENGR112 HW9 Matrices and Multis.pdf - Week 9 Homework Name:...

Week 9 Homework ENGR 112 Strings and Files
Name: Ziyi Jian Lab Time
(ECampus write “ECampus”)
: m 4 pm
Names of people you worked with:
•
N/A
Websites you used:
•
N/A
Approximately how many hours did it take you to complete
this assignment (to nearest whole number)?
6
By writing or typing your name below you affirm that all of the work contained
herein is your own, and was not copied or copied and altered.
Note: Failure to sign this page will result in a 50-point penalty. Failure to list people you
worked with may result in no grade for this homework. Failure to fill out hours
approximation will result in a 10-point penalty.

Week 9 Homework ENGR 112 Strings and Files
Learning Objectives:
• Making (and using) matrices to move things around
• Plotting curves in 3D using plot3
• Making and plotting surfaces using meshgrid and surf

Week 9 Homework ENGR 112 Strings and Files
Problem 1
Compute the total mass (g) of the rocket components shown in the table below using a dot
product. Print your answer in the command window.
)
50

Week 9 Homework ENGR 112 Strings and Files
Problem 2
An anti-symmetric cross-ply composite laminate has two layers in which the fibers are aligned
perpendicular to one another. A laminate of this type will deform into a saddle shape due to
residual thermal stresses as described by the equation
? = 𝑘(?
2
− ?
2
)
where x and y are the in-plane coordinates and k is the curvature. Make a surface plot showing
the deflection of a one-meter by one-meter square plate using - 0.5 ≤ x ≤ 0.5 m and - 0.5 ≤ y ≤
0.5 m. Assume k=0.77. Choose a step size that captures the shape but doesn’t have too many
points (use the same step size in x and y).
a) Use the
view
command to print four subplots as shown below, then add a
colorbar
to the
graph. Use
help graph3d
in the command window to find some different color maps, then use
colormap
to choose your favorite. Use
axis equal
to show the true deformation.
b) Now create a set of x and y sample points of the function using 3 sample directions in x and 4
in y . Use
interp2
to interpolate these sample points with the same mesh you used in part a).