Members Definition and 161 Threads

Homework Statement Homework EquationsThe Attempt at a Solution Was trying to solve for the horizontal reaction at B. Why is BC a two-force member but not AE?

Hello Integral and all the forum members, Before approximate 8 months I read that some big companies begin to invest a lot of money in change the wafer size from 300 millimeters diameter to 450 millimeters diameter, in these days one friend tell me that he hear that all the industries in...

Hey all! Did you know that one of our members (http://mathhelpboards.com/members/mathmari/) created a new math web site, just for fun? It's here: The Magic of Mathematics - Home Anyone feel like posting something (that is, using the contact form) there? ;)

Hi, I want to discuss the non-european members of Warsaw, Pact Eastern Bloc and Comecon. For example, whati is the situation for North Korea, China and India?

Homework Statement I want to find the force in the vertical purple member. Assuming I know the forces in all the other members, there's a problem with working out the force in the purple member. (Bear in mind, I'm using the method where I assume equilibrium at each joint in the...

Hi all, I have a textbook question which I am stuck on and should be quite basic. There is a bar that has a cross-sectional area of 1750mm2, and E = 220GPa. http://imgur.com/gU29J1q Edit: okay link is not working, it is http://imgur.com/gU29J1q I am asked to find the displacement with the...

what are the internal force in the hinged member 1-4?

Hi fellow PF members, I am an undergrad physics student in the last year of my degree. This year has been pretty sh**** as I have been rejected from 17/17 US universities that I had applied to for a PhD program. As a good and organized scientist though I had a backup plan. As I didn't really...

I've recently created a flickr's account because of my digital camera upgrade. I know a few of you are using flickr but I'm interested in knowing who exactly. So feel free to post! :smile: My account is http://www.flickr.com/photos/mygzulis/. Out of the 27 photos I posted there, I think only 1...

Hoping to get some assistance here on a volunteer project I am working on. I am writing a program for my bicyle club in preparation for our spring training series. We will have x participants that will be divided weekly into y number of (approximately) equal groups containing z members per...

Homework Statement I'm supposed to find the forces in each member and then determine whether they are in tension or compression. I got the magnitudes right but it seems my directions are wrong according to the book but I am confident that I did the question right. The diagram is part of a...

Homework Statement I have to write a ~2000 word essay using principles of fluid mechanics to address whether or not the frill on Triceratops is mainly for behavioral display or for thermoregulation. I'm not really that proficient in my knowledge of physics and have been struggling with quizzes...

Homework Statement The brake linkage for a truck is actuated by hydraulic cylinder AB. Cylinder AB, springs CD, EF, and GH are the slotted tracks are all horizontal. The slotted tracks are frictionless. If the cylinder AB exerts a tensile force of 12 kips, determine the deflection d and the...

How man of you preread for a math class? All members welcome, mods, homework helpers etc... Talking specifically about math classes. What if an instructor doesn't give the sections to read. When I do preread, it helps a lot to focus in class and gain more from lecture. Almost always otherwise I...

Homework Statement Determine the forces in members BC, CF, and EF of the loaded truss. Forces are positive if in tension, negative if in compression. I have included an image Homework Equations ƩM = 0 ƩFy = 0 ƩFx = 0 The Attempt at a Solution I'm a little stuck on this one. I...

Homework Statement There is a section in my book that has the same title as the title of this discussion topic. I understand the math just fine, so this is a conceptual question. In the book the cross section is shaped and oriented like a C, and it shows the shear flow flowing...

When browsing the forums and interacting with people, do you picture them in your head as being similar to their avatars? For example every time I think of Phinds I picture a big smelly dog licking my face. No Phinds! NO! Down! And Evo is a young maiden with long hair swinging slowly in a...

For the set G where G = {{b},{c},d,{∅}}, I believe these are correct: 1) {{c}} \subseteq G 2) {b} \subseteq G 3) {d} \subseteq G 4) d \subseteq G 5) ∅ \subseteq G 6) c \notin \varphi(G) 7) {c} \in \varphi(G) 8) {b} \subseteq \varphi(G) 9) {{d}} \notin \varphi(G) 10) ∅ \in \varphi(G)...

Is the set of all integers where <x,y> \in R if and only if (y = x + 3) & (y = x – 3) an empty set?

This is my first post on any message board so bare with me on any grammatical errors I make in the post. I will be heading into my senior year of high school and I plan on majoring in physics. But I live in a rather rural community and high school courses aren't considered challenging. We have...

Hello! I have this thermodynamical expression: dS=\sigma T^3 dV+4V\sigma T^2 dT+\frac{1}{3}\sigma T^3 dV=d(\frac{4}{3}\sigma T^3 V) Basically saying: \frac{4}{3}\sigma T^3 V=S Now, I do not get this.. d(expr) part, why are there three members to d(expr), with 2x dV and 1x dT.. nope...

Do you recognize other PF members?? Here are 8 quotes of PF members. Can you tell which member made which quote?? 1) Welcome to the PF 2) Well, for a while one of the biggest problems in experimental quantum mechanics was figuring out what to do with the mounds of dead cats out behind the...

Hi guys i have a exam coming up soon and stress is starting to kick in. I am good with stress and strain, but I am just confused on this question and don't understand what i need to be doing. I've tried every formula and i just can't seem to get question 5 out. The answears for this question is...

is there a simple way to determine the section modulus of a member made of a W and WT shape welded together, one on top of another about the x-axis. the steel manual has the properties for the individual sections; would the section modulus of each be able to be added together or will i have to...

#include <iostream> using namespace std; class B { public: int a,b; string c; B (int, int, string); B (); }; B::B (int d, int e, string f) { a = d; b = e; c = f; } B::B () { a = 0; b = 0; c = "Nothing"; } int main() { B Wibbly (1,2,"Wibbly"); B Wobbly (); cout <<...

Homework Statement Homework Equations torque = force x distanceThe Attempt at a Solution words: hopefully this one is clearer than the last one and someone can follow what I did and figure out where I went wrong. Thanks. Answer is Ffg=5kn T, Ffh = 20 kn T (only these two members are being...

Hi, I am trying to come up with a formula that will generate a price based on its cost. The only trick is that it can't be something constant like 20% or 30% more than the cost. It has to be a formula that adds a bigger profit on smaller numbers and lower profit on bigger numbers. So on a...

It was reported by 60 minutes that members of Congress may have benefited personally from information gained during the course of their work. This behavior is strictly prohibited on Wall Street - should the same rules apply to elected officials...

Homework Statement a) Find the reactions provided by the foundations at A and B. b) Use the method of Resolution at the Joints to calculate the forces in all the members. c) Which member will fail first and why ? Homework Equations ƩFx = 0 ƩFy = 0 ƩM = 0 The Attempt at a...

2 force members have to be collinear, is that the same way with 3 force members? Just a curious question.

Homework Statement Supposed to support a 50 kN weight at a pin joint at the center of a void as cost effectively as possible using trusses (e.g., trusses and pin joints have costs) Homework Equations Basic sum of moments and sum of forces = 0 The Attempt at a Solution Why can't I...

Homework Statement So I'm trying to do this problem right now. For the most part, I feel like I have 80% of the work done (in terms of finding certain unknowns etc) but I have no idea how to incorporate the θ=3°. What I mean is, what kind of equation can I set up that includes the angle...

HOW MANY PACKETS DO I HAVE TO BUY? Hi all, I'm posing this question because I'm interested in the answer from a purely theoretical point of view - I'm not going to go out and test the answer afterwards, and it's not for my homework (I last did homework more than 10 years ago)...

I have read many discussions on PF and it is a great resource. The members are very helpful to answer all types of questions and give their input. Unfortunately when dealing with responses to questions posed by "inexperienced" and overambitious (usually young) members it is easy to be to...

Homework Statement As shown, a load of magnitude P is applied to a structure. Assuming that all members are weightless and that ABEF and BCD are rigid bodies, find the magnitudes of the reactions at D and G needed to maintain the structure in equilibrium...

When I used to lurk around this forum about 2 years ago, I was frequently seeing users by the name of: - Chroot - Cyrus - a few others that I do not remember the name, but were fairly popular... Which leads me to ask what is the typical lifespan* of a PF member? *By lifepan I mean how many...

I've had to conduct an experiment with strain gauges attached to each member and when I've calculated the forces in the members I've come out with really large forces in comparison to the applied force.. how does this work out?

Homework Statement See attachment. Homework Equations Sum of Fx, Fy, and Moments=0 The Attempt at a Solution A and B are pins, so there is a x and y component at each of these points. Cable has same tension on either side, 1200. Take the moment at A to be zero...

Hi people new to this forum but i need some help on my thread design. I've been browsing the net for some time to try and find some help on the design of this but have not found much. My problem is i have a tubular member of 250mm outer and 100mm inner diameters that is subjected to an axial...

Hi gang. I need some help with a technical issue. I am an avid mountain biker, and one of the forums I post on has an ongoing discussion of whether or not the bottom spokes in a bicycle wheel support the load, or the upper spokes support the load. In a typical wheel the spokes are...

Homework Statement See attachment. Edit: Point A is a pinned connection (has a reactionary force in X and Y direction). Point B is a roller connection (only has reactionary force in Y direction) Homework Equations Sum Fx=0 Sum Fy=0 Sum of Moments=0 The Attempt at a Solution...

Jethro Tull, here's the short version https://www.youtube.com/watch?v=MBnyT2L6Okk https://www.youtube.com/watch?v=W7-EEGiABBU http://www.youtube.com/watch?v=rGQsC3qZeL4&feature=related https://www.youtube.com/watch?v=rGQsC3qZeL4&...

I missed it! We probably broke 250K last Thursday.

Hi all, Trying to design a simple gate for the side of our house and in order to select the size of the square tube for the frame, I need to calculate the forces in the members of the frame. I have tried the method of sections and joints, however both do not seem to work. My next...

please see the attached image, I'm supposed to find the internal force in each member of the truss. I used moments to find My=40 and Gy=120, I then moved on to FBD of joint G where I found Fgh=30kN in tension, and Fga=50kN in compression, next I did joint A to find Fab=30kN in tension...

Hi, I have a rather simple question, how does a binary system with a common center of gravity affect the gravity on both members of the system. If we have a case of a single planet and ignore the star it orbits, the center of gravity should be in the dead middle of that planet. If we...

URGENT: All PF members read. You are now aware that you are breathing. That is all.

Homework Statement N/A A 250-mm long aluminum tube of 36mm outer diameter and 28mm inner diameter may be closed at both ends by means of single threaded screw on covers of 1.5mm pitch. With one cover screwed on tight, a solid brass rod of 25mm diameter is placed inside the tube and the second...

Homework Statement see #3Homework Equations N/A The Attempt at a Solution I'm working on this assignment and I got stuck at this part in programming here's what I need to do: I need to find a way to have one object access the data members of another object. A broken down/simplified version...

Hi, I have to design a steel structured truss footbridge. Im using beam anology to determine the correct member sizes. Having trouble determining the maximum design moment (M*) Here's what I have calculated thus far: Q=6kN/m G=1kN/m 50m long, 3m depth, 3.125m spacing Self Weight...