# Search results

1. ### Hamiltons Principle on Moving Cart with Fixed Beam

Homework Statement -Use Hamiltons Principle Homework Equations \int _{t _{1}}^{t _{2}}({\rm }\delta T -\delta U -\delta V _{E }) dt} The Attempt at a Solution Here are my energy equations. So we have kinetic energy from the base and the beam. T_{{{\it beam}+{\it base}}}=1/2\,\int...
2. ### Near and Far Field Attenuation Inverse Laws

Homework Statement near-field distance attenuation follows an inverse cube law (1/d^3), while in the far-field it follows inverse law (1/d). Prove mathematically how we arrive at 60dB/decade from the inverse distance cube relation and 20dB/decade from the inverse distance relation...
3. ### System of ODE Boundary Value Problem with 2nd Order Backward Difference

{\frac {{\it du}}{{\it dx}}}=998\,u+1998\,v {\frac {{\it dv}}{{\it dx}}}=-999\,u-1999\,v u \left( 0 \right) =1 v \left( 0 \right) =0 0<x<10 Second Order Backward Difference formula {\frac {f_{{k-2}}-4\,f_{{k-1}}+3f_{{k}}}{h}} I'm trying solve this numerically in matlab, but can't seem to...
4. ### Choosing your TA's

Just wondering how the educators out there or departments choose their teaching asisstants. In my department, if faculty is teaching the course, then they tend to use their own students from their lab. If it's an outside professor, then the faculty professor in charge will probably ask HR to...
5. ### Nonlinear System of Equations Newton-Raphson and SOR Sucessive Over Relaxatiom

Homework Statement 3X1 - COS(X2*X3) – 0.5 = 0 X1^2 - 81*(X2 + 0.1)^2 + SIN(X3) + 1.06 = 0 EXP(-X1*X2) + 20*X3 + (10pi – 3)/3 = 0 Homework Equations Newton Raphsom and Gauss Sceidal with relaxation term The Attempt at a Solution I've already solved the above system using Newton...
6. ### Question About Grade Recording for the Instructors Out There

Thanks to budget cuts the class sizes have increased a lot, which makes the class roster on my excel sheet pretty long. After a couple of hours of looking through students different styles of hand writing, my eyes get a little fuzzy and it makes searching for students names on the spreadsheet...
7. ### Unknown DC motor Specifications

Me and another person were rummaging through one of my colleges labs looking for usable parts for my groups product design course. We found this medium size motor that weighed about 2-3 pounds. The problem is that there were no stickers at all that indicated its specifications. There were a few...
8. ### Anyone using the GSL 1300X Furnace by MTI Corp?

My lab just bought the GSL1300-40X Desktop Alumina Tube Furnace from MTI recently. This thing has been a total headache to install and operate. The lab manager was totally confused about the wiring. The instructions were obviously written by someone who did not speak English well. Then there was...
9. ### Resume Feedback, Mechanical Engineering student

Can someone read over my resume. Thank You Here is the file. I uploaded it this site, because I don't know when an Admin will ok the file. http://www.badongo.com/file/7507007 I replaced a lot of the names with generic stuff since this is a public form. Couple of things that I was unsure...
10. ### Resume Question about Research Experience and Publications

At this moment I am typing up my resume for an engineering career fair coming up this week. I lost my resume doc from last year, so I have to type it up from scratch and memory. The old one was pretty standard like objective, education, experience etc. I did some volunteer undergrad research...
11. ### MATLAB Matlab: Saving and Running M-files

I've noticed a weird thing that Matlab does whenever I save my m-file then try to run it. If I save my M-file with a simple file name like "HW4" or "untitlited" it will run. However if i save my m-file as file name HW#4_3.40 (I just wanted to label the file with the problem # from the text I'm...
12. ### Advice on undergraduate summer research positions

During last 2 weeks I've been running around asking (mostly e-mailing cause they are rarely in their offices) professors in the fields of solid and structural mechanics for research positions. I got a late start cause I didn't know when to start looking for positions. Turns out at my college 6th...
13. ### 2nd Order DE with undamped motion

Homework Statement Solve the initial value problem u\prime\prime+u=0.5cos (0.8t)\\ u(0)=0 \ u\prime(0) = 0 Homework Equations u(t) = [A*cos (w_nt)+ B*sin (w_nt)] + \frac{F_0}{m(w^2_n-w^2)} \left\{\begin{array}{cl} sin(wt)\\ cos(wt) \end{array}\right. The Attempt...
14. ### Checking for time invariance

Homework Statement Consider the following input-output relationship: y(t) = \int_0^\infty e^{-\sigma}x(t-\sigma) d\sigma A) Is the system time-invariant? B) Find the output y(t) when the input to the system is x(t) = \mid t \mid , -\infty < t < \infty Homework Equations These are the...
15. ### Kinematics of a Particle Tangent-Normal components

Homework Statement http://img136.imageshack.us/img136/1930/carrs8.th.png [Broken] Homework Equations a = (v^2/p) en + (v*)et a- accel v-velocity en- inward normal et- unit vector along tangent v*- tangential acceleration p- curvature The Attempt at a Solution FOr the first part I just need...
16. ### Kinematics of Particles

Homework Statement http://img402.imageshack.us/img402/5733/problemvm7.th.jpg [Broken] I had to draw in that line. It was suppose to show a dotted line of the projectile, but the page did not scan well. Homework Equations The Attempt at a Solution First atempt...
17. ### Need a Fluid Mechanics Text

Someone recommend a Fluid Mechanics text for an introductory course. And to understand the position I am in at the moment bad professor, TA and text ( Fluid Mechanics by Frank M. White) My library has a few old fluids text, and the ones I flipped through were Fundamentals of Fluids by...
18. ### Fluids mechanics Helium balloon

A spherical helium balloon is 2.5 m in diameter and has a total mass of 6.7 kg. When released into the U. S. Standard Atmosphere, at what altitude will it settle? My first thought was that diagram has the weight of the balloon acting downward, buoyant force upwards. -weight + Fb = 0...
19. ### Fluid Mechanics Forces on Curved Surfaces

Not really a hw problem, but I'm having a hard time with this section. It's mostly dealing with the horizontal component of the force. This is from my book, Fluid Mechanics by frank m white 5 th ed, "The horizontal component of force on a curved surafce equals the force on the plane area...
20. ### Vectors with appl of dot product

I'm trying to solve this problem with different approaches. Link is here http://img138.imageshack.us/img138/2268/problem1eb1.th.png [Broken] the answer is 0i + 0.0927j + 0.0232 k lb * Means DOT Method one: Find the force in scalar components. Then Take the cross product of two position...
21. ### Fluid Mechanics question (shear stress)

The problem and solutions is here http://img206.imageshack.us/img206/6093/problem1rm4.th.png [Broken] Isn't the shear stress for both the inner and outer negative? When i take the derivative i get negative. The derivative is basically ln ( 1/x) since the rest are just constants. Edit: I meant...
22. ### UCLA or Cal Poly San Luis Obispo Mechanical Engineering

I got accepted to both schools as a transfer student form a community college. i'm having trouble deciding where to go, because both colleges have very good engineering programs. I think about it every freaking day, but mostly cause people keep asking if i have decided yet. :uhh: Most of the...
23. ### Recommend a Statics Book

Posted in different section decided to move this post here I'm currently using Statics: Analysis and design of systems in equilibrium by Sherri D sheppard. My classmates and I want another statics book for reference. We are looking into Vector Mechanics for Engineers, Statics and...
24. ### Recommend a statics book

I'm currently using Statics: Analysis and design of systems in equilibrium by Sherri D sheppard. My classmates and I want another statics book for reference. We are looking into Vector Mechanics for Engineers, Statics and Dynamics 7e Ferdinand P. Beer (Author), Jr., E. Russell...
25. ### Statics: Mechanical Equilibrium

I need some help in this problem to see if my game plan is right. My answer doesn't make sense, well to me it doesn't. A weight of 200 lb hangs from a frame of negligible weight, as shown. If the frame is in equilibrium, determine the loads acting on the frame at A and D. Use the fact that...
26. ### Projection of vectors

I was copying my friends notes and had a hard time understanding one of the examples he had written down from lecture. See the attachment for a the picture of the example. This example looks like a projection of two vectors to me, but i'm not sure. u'=\frac{4i+2j}{\sqrt{20}} u' = unit...
27. ### Srping Problem

Spring Problem I need some help or hints on this exercise When a certain linear spring has a lenth of 180mm, the tension in it is 170N. FOr a length of 160mm, the compressive force in the spring is 130N. a. What is the stiffness of the spring in SI units? In U.S. Customary units? b. What...
28. ### Initial Value Problem question

i was taking my final today and came across an initial value problem. Seemed pretty simple, seperate the variables, integrate, then use the initial value to find the value for the constantt C. The weird thing was that the constant C would be multipled by 0 when i plug in the given initial...
29. ### Programming a parallelogram in C++

I'm having troube getting my program to display a parallelogram. The source code here just displays a triangle with "6" as the speicifed size. * ** *** **** ***** ****** ***** **** *** ** * The output is suppose to be something like this: _____* _____** _____*** _____****...
30. ### Finding Resistance and Inductance of solenoid

The inductance of the solenoid determines the time it takes to establish this current. Find the inductance,the resistance, and the time constant of a solenoid that is constructed by wrapping five “tightly wound” (i.e., wire-against-wire like this ) layers of 0.30 mm diameter copper wire on a...