Hi Ken.
Sorry if this answer is too late. I went back at 38 and am now a working structural engineer. Be very sure about your choice. The degree is challenging to say the least. In addition to the hard work, etc., I always felt a little out of place. I had no trouble getting employed and...
Okay. Bear with me...
If the force I'm finding doesn't act through the point I'm taking the moment about.
Say A is rigid connection... I'll have Ax, Ay and Mx. I have a known point load acting somewhere along the beam and I want to find 'By' located a certain perpendicular distance from...
Homework Statement
If I take a moment around a point with a rigid connection what forces do I eliminate at that connection?
If I have a reaction force in the Y direction, a reaction force in the X direction and a moment at that point can I eliminate Ry, Rx and Mx or does Mx remain.
Can...
Homework Statement
\int\intD\left|x\right|dA
D= X2+y2<=a2 where a>0
Homework Equations
\int\stackrel{\Pi/2}{0}\int\stackrel{a}{0} r cos \Theta r dr d\Theta
I hope that's clear...
I evaluate this to \frac{a^3}{3} sin \Theta
sin \Pi/2 = 1
so I get \frac{a^3}{3}
the...
Okay. Here is what I have..
\frac{log A}{log B} = \frac{2}{3}
3 log A = 2 log B
log A3 =log B2
log A3- log B2 = 0
log \frac{A^3}{B^2} = 0
\frac{A^3}{B^2} = 1
A3 = B2
from the question, we know that \frac{A}{B} = \frac{2}{3}
B = \frac{3}{2} A
(\frac{3}{2}A)2 =A3...
Homework Statement
A professor is doing a problem on the black board and ends up with the expression
\frac{Log A}{Log B} = \frac{2}{3}
.
He absentmindedly cancels the “log”, making the left-hand side A/B. (A very wrong thing to do!)
Luckily, he ends up with the correct values for A...
Okay, I got it.
(A+I)(A-I)=I
A2-I2=I
A2=2I
(A2)51=(2I)51
A102=251I51
since I51=I
(A102)-1=(251I)-1
A-102=2-51I
A-101xA-1=2-51I
A-101=2-51IA
A-101=2-51A
since originally, A-101=2axA
a must equal -51
thanks for all of your input.
I don't see how it is supposed to be an I on the right side instead of 1.
If I have (A101)-1 that's just 1/A101.
If I multiply through by A101 then don't I have a 1 on the right side?
I tried this;
(A101)-1=2aA
\frac{1}{(A^2)^5^0}=2a
2I-50=2a
Okay.
A2=I+I2
A=\sqrt{I+I^2}
2aA102=1
I don't see a substitution that will help there.
I didn't know I could expand the first equation.
I'm not sure if I even multiplied through by A101 correctly.
Homework Statement
Find "a" when A is a square matrix satisfying (A+I)(A-I)=I and (A101)-1=2axA
I is the identity matrix.
The Attempt at a Solution
I'm trying to find A. I didn't know where to begin, so I picked A to be all zeroes and plugged it in the equation. It didn't work...
I tried...
Homework Statement
r(t)=(cos t +tsint)i + (sin t -tcost)j + 3k
Homework Equations
dr/dt=v(t)
The Attempt at a Solution
when I take the derivative of r(t) I get;
v(t)=(-sin t + tcost)i +(cos t +tsint)j
the book says;
v(t)=(t cos t)i +(tsint)j
could some one tell me why? Where...