# Search results

• Users: mpm
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1. ### Hardness vs Brittleness Aluminum

I don't have any kind of numbers, facts or figures on me, but I am a material engineer. Generally, whenever a material is hardened, it becomes more brittle in a sense. It doesn't mean that it becomes brittle, but the material loses its ductility. That is the reason for say annealing. It...
2. ### Biomechanics HW Problem

The answer I came up with is about 9500 N. Is this possible?
3. ### Biomechanics HW Problem

Here is an attachment of what my assignment is.
4. ### Biomechanics HW Problem

After doing some research, I have come to the conclusion that if i neglect torque, then I don't even need to worry about moment of inertia. Is this correct? I can't find any equation that relates linear motion with moment of inertia unless there is torque involved. Is this correct?
5. ### Biomechanics HW Problem

I have a Force Acceleration analysis that I am un sure of. I have a picture of a skull that is punched/kicked/whatever in the chin. Problem Statement: The head shown in the figure below is considered a rigid body. IT rocks on the occipital condyle, C, where an axial force, Fa, and a...
6. ### Creating a Car Model for Turning: Dynamics Knowledge Needed

http://www.me.ttu.edu/UserFiles/File/Maxwell%20Spr%2006%20Auto%20Sys/Intro%20to%20vehicle%20dynamics%201.pdf Try that file. Those are notes from an automotive class being offered at my university. I can't tell you how long those will be up so you may want to save them. Hope this helps.
7. ### High speed train aerodynamics

Since it is a train, it should be the same principles used on cars. The aerodynamics should be very very close if not identical. http://www.me.ttu.edu/UserFiles/File/Maxwell%20Spr%2006%20Auto%20Sys/Accel%20&%20Res%20to%20Motion.pdf Try that file. I don't know how long it will be up so...
8. ### Canard Configuration and Sum of Moments

LC is lift due to canard LW is lift due to wing Alpha is the angle of attack for the wing. aw is lift curve slope of the wing hn is the distance to the neutral point hcg is the distance to center of gravity I believe you are right on the moment arms being the l's. CMcg is...
9. ### Canard Configuration and Sum of Moments

I'm in an aerodynamics class, and I have this canard configuration I'm trying to figure out for a final exam. I need to find the sum of the moment about the center of gravity. I may cannot be helped without the drawing being posted. So far this is what i have: Mcg = Mac - (lcg + lw)Lw +...
10. ### Pressure vs. Velocity Problem

So am I to assume that the pressure needed to propel the ice a certain velocity cannot be solved theoretically without taking a long time to do? My professor wants me to do it, but I don't know if it can be done. I have talked to 2 other professors who haven't lead me in the right direction...
11. ### Pressure vs. Velocity Problem

This isn't a homework question; however, it is probably similar to one. I am doing a design project that involves a hail cannon. Basically I have created an air gun that propels ice balls. I have a compressed air tank, with an electronic quick release valve and then a barrel made of PVC...
12. ### Zero Mach number lift coefficient

I have some aerodynamics homework to finish up, and I am not really sure how to do one part. Question is: What is the corresponding zero Mach number lift coefficient I can't find an equation in my book or anything. Can someone maybe shed some light? My first two questions were to...
13. ### Help needed with 2 physics questions

I need help with 2 questions that I can't seem to figure out. I had them for homework but I never got it right and the homework has since been turned in. I was told I would most likely see these problems again on the exam. Therefore I need to learn how to do them. Can anyone help me out on...
14. ### Electric Field Homework Question

I am having difficulty with this homework question. I am not even sure whether to start. Question: A molecule of DNA lies along a straight line. It is 1.061 micrometers long. The ends of the molecule become singly ionized; negative on one end, positive on the other. The helical...
15. ### Will PVC be suitable for this design?

I realize I made the description kinda worried. Basically I have a 3" diameter barrel, connected to a 1" Quick Release Valve, that's connected to a 2" expansion chamber which is connected to an air regulator and on the other side of the regulator is where the air hose will be connected...
16. ### Will PVC be suitable for this design?

I talked with my group members and we had a new idea for the gun. One that might make it cheaper, safer and easier to work with. What is yalls opinion of this design? We will be working in a lab so we will have a compressed air hose around us at all times. What if we made the barrel out...
17. ### Will PVC be suitable for this design?

Thanks for all your help on this Fred. The design isn't final by any means. I am just having to do a proposal for it. I will look into steel for the pressure vessel and see what I can do. Who knows, maybe I can pull it off and get one. Thanks again.
18. ### Will PVC be suitable for this design?

We were planning on placing the gun before a velocity meter. We plan to have an air regulator. Then just pick a pressure and fire it past the velocity meter and get the according velocity. Once we find the pressures that relate to a certain velocity for each diameter hail, we will know what...
19. ### Will PVC be suitable for this design?

I'm actually in college. I will be using this gun to test building materials for impact damage. I'm trying to see if these coatings they put on sheet metal are actually effective or not. I will be using compressed air only. I really don't know how much use this thing will get. I'm not...
20. ### Will PVC be suitable for this design?

70 psi is about 483 kilopascal. Does that help any?
21. ### Will PVC be suitable for this design?

This may help clear things up a little. You still may not be able to give an answer. I've decided to change the design slightly after typing that first one. The pressure reservoir will be 3" Schedule 40 PVC that is 24" in length. It will have a 3" end cap that is cemented on. I will...
22. ### Estimate time to reach steady state

I have some first order differential equations. I have found the steady state response for each equation. However, now I need to estimate how long it will take to reach steady state. Can anyone tell me the formula for that or get me started on how i go about doing this. I'm not finding...
23. ### Will PVC be suitable for this design?

I am designing a hail gun for my senior design project. I am needing about 70 psi of pressure for my maximum pressure. I am going to use various diameters of Schedule 40 PVC. The max pressure rating for this diameter is 220 psi at 73 degrees F. However this is for water. I've seen articles...
24. ### Can someone check my work?

I did it a different way for Problem 1. I made the equation into 6*vdot + 24*v = 2700. Then I solved for V(t) which is the free response and force response. Since v(0) = 0, the free response goes away. leaving v(t) = F/c(1-e^(-ct/m) = 2700/4*(1-e^-4t) I then took the integral of...
25. ### Finding the antiderivative for fractions?

There is no need to take out the 4x. You are corrrect that the x's will cancel out leaving you with the integral of 4dx. This will give you 4x + c unless of course it integral is bounded. The derivative of 4*x is 4. So it is true that what you said is all equal. what you are probably not...
26. ### Partial Fractions/Laplace Transforms

I have the transfer function X(s) = (18s+10)/(s(3s^2+18s+10))/ I need to break it up into partial fractions so i can take the Lapalce transform and get it into a response. I can't figure out what it breaks up into though. I know its 3 partial fractions and one of which is 1/s I believe...
27. ### Can someone check my work?

So I should have a variable still I guess for my v(t) instead of setting it to equal 0. Can you give me an idea of what it might equal?
28. ### Can someone check my work?

Ive got 2 questions that I would like looked at. Question 1: A rocket sled has the following equation of motion: 6vdot = 2700 - 24*v. How long must the rock fire before the sled travels 2000 m? The sled starts from rest. I took the integral which of that equation which gamve me v(t) =...
29. ### Determining head versus flow rate curve.

I'm doing a lab on Laminar Flow Elements - Fan Performance Test. So far I have had to find power coefficients (CP), discharge coefficient (CQ) and head coefficients (CH). I've plotted CH vs. CQ, CP vs. CQ and Efficiency vs. CQ. My last requirement is that I "Use the curve fits to...
30. ### Complex Eigenvalues

I know what complex numbers and eigenvalues of matrices are. I just didnt really know what the question meant by "geometrically show".
31. ### Complex Eigenvalues

I've got a homework problem that I am needing to do; however, I am not sure really what the question is asking. Obviously since I don't know what is being asked, I don't know where to begin. I was hoping for some insight. Question: Show that matrix A = {cos (theta) sin (theta), -sin...
32. ### Eigenvectors, Eigenvalues and Idempotent

I have a question that deals with all three of the terms in the title. I'm not really even sure where to begin on this. I was hoping someone could help. Question: An n x n matrix A is said to be idempotent if A^2 = A. Show that if λ is an eigenvalue of an independent matrix, then λ must...
33. ### Gram-Schmidt Process Question

Doesn't anyone possibly know the answer to this question? Or can anyone even give me some direciton on it?
34. ### Gram-Schmidt Process Question

I have a question about this process. What will happen if this process is applied to a set of vectors {v1, v2, v3} where v1 and v2 are linearly independent, but v3 belongs to set Span(v1,v2). Will the process fail? If it fails, why does it fail?
35. ### Converting Linear Equation to Angular Equation

I just found something. Im thinking k = ω^2*m So that makes this ω^2*m*Θ and m = I so my final equation is IΘ'' + (g/L)Θ' + ω^2IΘ = 0 Does this look right?
36. ### Converting Linear Equation to Angular Equation

Well so far I have: IΘ'' + (g/L)Θ' + ? = 0 I used the small angles approximation which got rid of the sin(Θ'). Can anyone help me turn the kx itno angular terms? I know x goes to Θ but not sure about the spring constant.
37. ### Converting Linear Equation to Angular Equation

Can anyone help me convert this linear equation to angular terms? mx'' + f*sin(x') + kx = 0 x'' = x double dot x' = x dot Im having trouble find info on changing this.
38. ### MATLAB Plotting Transfer Functions Using Matlab

I figured out how to get the zeros, poles, and gain by using this: num = [2 3]; den = [1 4 0 5]; [z,p,k] = tf2zp(num,den) But I can't figure out how to plot this to find the frequency response and bandwidth. Note: I am just trying to find alternatives since I can't get...
39. ### MATLAB Plotting Transfer Functions Using Matlab

I am using a bode plot program using Matlab to try and plot transfer functions. Here is the program I have: http://www.swarthmore.edu/NatSci/echeeve1/Ref/Bode/BodePlotGui.html [Broken] Everytime I try and type in the command that it says to use, it gives me a tf is an unknown variable...
40. ### Need help with a linear algebra proof

I have another problem that I am needing a little guidance. Problem: Let L be a linear operator on R1 and let a = L(1). Show that L(x) = ax for all x belongs to set R1. Do i just need to use the definition of a linear transformation and show that this is a linear transformation or what?
41. ### Linear Transformations

I also forgot to add this part to prove the second part. L(p(x) + p'(x)) = x(p(x) + p'(x)) = xp(x) + xp'(x) = L(p(x)) + L(p'(x)) I think this should be right but would like to be corrected if wrong.
42. ### Linear Transformations

Ok I think I might have it this time. Can someone tell me if I am correct? L(a(p(x)) = x(ap(x)) = a(xp(x)) = aL(p(x)) Does this look correct?
43. ### Linear Transformations

Ok I see what you mean. Maybe I will get this straight sometime. I am terrible at linear algebra. Calculus and differential equations are more my thing.
44. ### Linear Transformations

Im curious if i can do it this way. It just came to me and I may be breaking a rule. Can I put: L(xp(x)) = xL(p(x)) = xp(x) And that satisfies my question?
45. ### Linear Transformations

So the x is used as a constant basically which is practically the original definition?
46. ### Linear Transformations

Yes I knew the two statements that you wrote. I guess I may just be a little unclear on how to handle this problem as far as notation goes. I have some work and an answer. Does this look sound? L(a*p(x) + b*p(x)) = L(a*x*p(x)) + L(b*x*p(x)) = a*x*L(p(x)) + b*x*L(p(x)) Therefore this...
47. ### Linear Transformations

Can anyone at least tell me how to get started on this problem I have? Problem: Determine whether the following are linear transforatmions from P2 to P3. L(p(x)) = xp(x) I understand when it's in vector form but not really picking up on the polynomial part of this.
48. ### MATLAB Quick and Easy Matlab Question

I am trying to plot transfer functions and find their resonance frequency and bandwidthy. Apart with me being weak in Matlab knowledge, I kinda know how to do the programming because of examples on the internet and book. However, every example talks about using a bode command. I try to...
49. ### Deteriming resonant frequencies

For some reason, I still can't get anything to come out of what you suggested. I understand what you are saying but its just not working. Anyone have other comments that might help? Mike
50. ### Deteriming resonant frequencies

I am stumped on how exactly to do this. I have the function: T(s) = 7/s(s^2+6s+58) I need to change this to T(iω) and i being a complex root. This creates: T(iω) = 7/(ωi*(ω^2+6iω+58)) I know I need to plot this function and find out where omega peaks and this will be my resonant...