Homework Statement
What are the potential errors in measuring strain with strain gages? How can these
errors be minimized?
The Attempt at a Solution
In my class notes, I have the four Errors.
1-Gage mounting (glue thickness & flex)
Use a thin layer of glue and make sure the layer is...
Wow, thank for the quick reply.
I know that, but don't you times it by 10 V? Isn't the units for resolution volts? I assumed when they said "resolution of 0.01%," I assumed this was .01% of the full scale voltage. Is that wrong to assume?
Should resolution just equal .0001? Then N= 16.6 = 17...
Homework Statement
An A/D converter is to operate with a full-scale voltage of 10V. How many bits should be employed to obtain a resolution of 0.01%?
Homework Equations
Resolution = Full Scale voltage / (2N - 1)
The Attempt at a Solution
.01% * 10 V = .01/100 * 10 V = .001...
Homework Statement
http://img843.imageshack.us/img843/5370/helpxd.jpg [Broken]
Homework Equations
Sin law
The Attempt at a Solution
I got to:
F1/sin(105) = F1u/sin(45) = F1v/sin(30)
I get F1u = - 219 and F1v = 254.5.... It says it is wrong, not sure what I did.
Homework Statement
S P^4 e^-P DP
Homework Equations
My parts.
The Attempt at a Solution
I know you can do u = P^4, and DV = e^-P
Then, you get du = 4P^3 dx and V = -e^-P
-P^4 e^P + S 4P^3 e^-p dx
Now, I can just repeat that for the intergral until I get to were the P...
Homework Statement
by expanding the binomial show that ( (Sqtroot(3)/2) + (1/2)i )^4 = ( (-1/2) + (sqroot(3)/2)i )
The Attempt at a Solution
I'm stuck, I now ( (Sqtroot(3)/2) + (1/2)i )^4 = ( (9/16) + (1/16)i )
But that's all I got, don't know the next steps.
Homework Statement
Using Gaussian Elimination:
3x - 2 y = 5
6x-4y =7
The Attempt at a Solution
[ 3 -2 5]
[6 -4 7]
* top row by 1/3
[1 -2/3 5/3]
* Top row by -6, add to bottom row:
[0 0 -3]
So I get this:
[1 -2/3 5/3]
[0 0 -3]
How can 0y equal -3?
Homework Statement
Convert the equation to a first order system.
d^2y/dt^2 + 3dy/dt + 2y = 0
The Attempt at a Solution
Set d^2y/dt^2 = dv/dt
dy/dt = V
So, I now have: dv/dt + 3v + 2y = 0
Now, i'm not sure what to do with that Y, In my notes we only did examples with...
Homework Statement
Find all Equilibrium points for the following systems.
B. dx/dt = 5x - x^2 - 3xy
dy/dt = 8y - 3xy - 3y^2
The Attempt at a Solution
0 = x(x + 3y - 5)
0 = y(y + x - 8/3)
Equilibrium points: (0,0) but I can't find anymore? is (0,0) the only one?
I think I set y(t) to 0. If this is the case, I get:
0 = -100e^(-1/20t) + 150e^(-1/40t)
How do I get rid of the e's? I'm not sure how with the numbers is front. Without the numbers in front I know I could rise them to ln.
Homework Statement
http://img262.imageshack.us/img262/678/im000724.jpg [Broken]
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The Attempt at a Solution
http://img843.imageshack.us/img843/5651/im000726.jpg [Broken]
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I got all the way to g, but I don't know how to...
oh, yeah... I meant 4t + c......So the whole answer is y(t) = {4t + C}/e^{t^2} (The e^{t^2} is under both).....Yeah, I second guess myself way too much. Most the time, after I ask for help, I realize how easy a problem was and can't believe I ask for help.
Homework Statement
Solve the differential equations [Find the general solution y(t)=KYh(t) + Yp (t)]. Use the method of finding the integrating factor.
dy/dt = -2ty + 4e^-t^2
The Attempt at a Solution
S = intergrat
dy/dt = -2ty + 4e^-t^2
dy/dt + 2ty = 4e^-t^2
P(t) = 2t
b(t)...
Thanks, that make senses. So basically the equilibrium points are the same as sin y. -2pi, -pi, 0, pi, 2pi....etc but they are all nodes due to being always positive because sin^2 y = 1-cos^2 y.
I know what a sink, source and node are. Sink, both sides are going to it. Source, going away, node is both. Don't you have to put it in your calculator to see what they are doing between equilibrium's?
After I find the equilibrium points I have to determine if they're a sink, source or a node. Since I can't put it in my calculator, how do I determine that? Are they the same as sin y or the opposite?
Homework Statement
I need to find the equilibrium solutions
dy/dt = sin^2 y
The Attempt at a Solution
I don't know what to do with the sin^2. If it was just sin, it would be easy, 0, pi, -pi, 2pi, -2pi.....etc...... But it's not, I have a Ti-84 plus calculator. So, i don't...
I think, I just started putting the t's in for t and the y's for y.... So for the first line I got:
K: 0
t:0
y:0.5
dy/dt(t,y) = .25
Change in t*dy/dt(t,y) = .125
Homework Statement
dy/dt = y^2-4t - y(0) = 0.5 - 0 <_ t <_ 3.0 - Change in t = 0.5
I have to use Euler's method to make a table, but I'm not sure how to handle the t. I have only done it with y's and no other variables.
I don't know the answer, but it does need to be P (t) = F(t). Because after we are done, we need to use a few initial conditions.... P(0)= 3, P(0)= -1/2, P(0)= -2.
How do you handled after this point though. The other I knew how to do, just made a few little errors.
I know, LN A - LN B = LN A/B
I also know, 1/A LN |B| = LN Aroot of B
Once I get them all to LN Some-Root B, I can get them all to the same LN. and will I take the e of both sides the LN is...