## Matlab Assignment 8

### Re: Matlab Assignment 8

F11Carrie wrote:The assignment file that was emailed out has a typo in Problem 2. The label should be "Torque" rather than "PointForce." Using something like "PureTorque" might make parsing simpler - also more precise.

Amen to that.

Dan

### Re: Matlab Assignment 8

Here is my coefficient matrix.

Qa =[0 -19.6 2.5 5 -19.6 0]'

The horizontal force does not create a torque in the initial horizontal arrangement

Qa =[0 -19.6 2.5 5 -19.6 0]'

The horizontal force does not create a torque in the initial horizontal arrangement

### Re: Matlab Assignment 8

Here's my coefficient matrix and RHS

Also note: I believe part (f) in the homework has a typo. Q2A is only 3 dimensional, not 6.

Also note: I believe part (f) in the homework has a typo. Q2A is only 3 dimensional, not 6.

### Re: Matlab Assignment 8

My plots for the matlab homework

Right Hand Side:

0

-19.62

2.5

5

-19.62

0

0

0

0

0

Coefficient Matrix:

2.000 0.000 0.000 0.000 0.000 0.000 1.000 0.000 1.000 0.000

0.000 2.000 0.000 0.000 0.000 0.000 0.000 1.000 0.000 1.000

0.000 0.000 0.167 0.000 0.000 0.000 0.000 -1.000 0.000 1.000

0.000 0.000 0.000 2.000 0.000 0.000 0.000 0.000 -1.000 0.000

0.000 0.000 0.000 0.000 2.000 0.000 0.000 0.000 0.000 -1.000

0.000 0.000 0.000 0.000 0.000 0.167 0.000 0.000 0.000 1.000

1.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 1.000 -1.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

1.000 0.000 0.000 -1.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 1.000 1.000 0.000 -1.000 1.000 0.000 0.000 0.000 0.000

Right Hand Side:

0

-19.62

2.5

5

-19.62

0

0

0

0

0

Coefficient Matrix:

2.000 0.000 0.000 0.000 0.000 0.000 1.000 0.000 1.000 0.000

0.000 2.000 0.000 0.000 0.000 0.000 0.000 1.000 0.000 1.000

0.000 0.000 0.167 0.000 0.000 0.000 0.000 -1.000 0.000 1.000

0.000 0.000 0.000 2.000 0.000 0.000 0.000 0.000 -1.000 0.000

0.000 0.000 0.000 0.000 2.000 0.000 0.000 0.000 0.000 -1.000

0.000 0.000 0.000 0.000 0.000 0.167 0.000 0.000 0.000 1.000

1.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 1.000 -1.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

1.000 0.000 0.000 -1.000 0.000 0.000 0.000 0.000 0.000 0.000

0.000 1.000 1.000 0.000 -1.000 1.000 0.000 0.000 0.000 0.000

### Re: Matlab Assignment 8

Quick note: I noticed that half of us have one answer for J' and the other half have another answer. I'm guessing the discrepancy is that the formula for calculating J' in Table 6.1.1 shows the length of the rod to be l1 with the distance from the origin to the end of the rod being l1/2 on each side. The figure for this problem has each half-length of the pendulum links being either l1 or l2, so body 1 has a total length of 2*l1.

### Re: Matlab Assignment 8

Good call Carrie on each segment length being 2L

Here's my corrected matrices:

Here's my corrected matrices:

### Re: Matlab Assignment 8

LeftMatrix =

Columns 1 through 7

2.0000 0 0 0 0 0 1.0000

0 2.0000 0 0 0 0 0

0 0 0.6667 0 0 0 0

0 0 0 2.0000 0 0 0

0 0 0 0 2.0000 0 0

0 0 0 0 0 0.6667 0

1.0000 0 0 0 0 0 0

0 1.0000 -1.0000 0 0 0 0

1.0000 0 0 -1.0000 0 0 0

0 1.0000 1.0000 0 -1.0000 1.0000 0

Columns 8 through 10

0 1.0000 0

1.0000 0 1.0000

-1.0000 0 1.0000

0 -1.0000 0

0 0 -1.0000

0 0 1.0000

0 0 0

0 0 0

0 0 0

0 0 0

RightMatrix =

0

-19.6200

2.5000

5.0000

-19.6200

0

0

0

0

0

Columns 1 through 7

2.0000 0 0 0 0 0 1.0000

0 2.0000 0 0 0 0 0

0 0 0.6667 0 0 0 0

0 0 0 2.0000 0 0 0

0 0 0 0 2.0000 0 0

0 0 0 0 0 0.6667 0

1.0000 0 0 0 0 0 0

0 1.0000 -1.0000 0 0 0 0

1.0000 0 0 -1.0000 0 0 0

0 1.0000 1.0000 0 -1.0000 1.0000 0

Columns 8 through 10

0 1.0000 0

1.0000 0 1.0000

-1.0000 0 1.0000

0 -1.0000 0

0 0 -1.0000

0 0 1.0000

0 0 0

0 0 0

0 0 0

0 0 0

RightMatrix =

0

-19.6200

2.5000

5.0000

-19.6200

0

0

0

0

0

### Re: Matlab Assignment 8

Here are my coefficient and right-hand-side matrices:

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