Member Definition and 246 Threads

Hey everyone, first of all I'd like to point out that I do plan on becoming an active part of this community, because I love physics! That being said, I am currently a sophomore in college and am currently taking a bunch of EE classes because I had decided to try to get into the EE program at my...

I am a new member here at Physics Forums, I am currently a University student in my final year of studying Cyber Security and Networks,i look forward to helping out if i can and learning more on my subject area, nice to meet you all.

Hello, I am a new member. I am interested in starting a forum about quantum gravity, still trying to figure some things out.

I was an APS member for a while, but when finances got tight I started wondering why I was spending so much for it. As I saw it, there were three benefits—a mailaps.org email address, APSNews, and discounts on conferences (which I couldn't afford to go to anyway)—which didn't seem worth the...

Two steel straps are use to hold member BCD level. The size of each strap is 12 mm thick and 50 mm wide. A 16 mm diameter bolt is used to connect thesteel straps to the 89 x 89 mm post at A. A 25 kN is applied at the free end of the cantilever at point D. Determine: the tensile stress developed...

Dear PF Forum, I just saw interesting windows at the bottom right corner of PF website. Total 964(members: 39, guest:837, robots: 88) That's a every interesting statistic. So when we post something and don't get answer immediately we'll know that at that moment PF Forum is a rather quiet, just a...

Hi! Nice to meet you all! Like you guys, I am also fond of reading science articles and brainstorming for better ideas that can help us in the future! No, I am not a genius or whatsoever however Like I said I am just here to enjoy reading physics and science stuff and make friends and We might...

Homework Statement Homework Equations ΣF=0 ΣM=0 The Attempt at a Solution I think i correctly identified two 2 force members at A and B. But would the system be a 3 force member? If it is i don't quite know how to solve for the missing angles. Is the problem asking for the sum of the...

I have never found sound to be a problem until now. I live on a street where, with the exception of cars, the side walks and the street are unobstructed concrete. My second story bedroom window directly faces a dryer vent that sits at street level across the street. The dryer, when on, produces...

I've seen some members having badge Mentor, and sometimes Science advisor, then Education advisor, Homework helper, etc.. How many badge are all there in PF? And what do they mean? Thanks

Hello! My name is Brenna Bruce and I am 15 years old. This past year I have discovered my thirst for knowledge about the universe. How it works and what makes it work (to my understanding is explained by mostly physics) are concepts I want to be able to grasp. My question for anyone reading this...

would rather make my debut appearance on a legitimate science thread but i wanted to respect this thread. :angel::sleep: don't know what else to say other than I am really into sciences, especially physics. (obviously)

I'm glad I found these forums as physics is a hobby of mine. I hope to learn a lot from here. A pleasure to make your acquaintance.

Hi all, I was just wondering if someone could confirm that my answer to the below question is correct. The point where the question asks you to find the shear stress is at 2m (n). However, I don't believe this value needs to be included in the calculation anywhere?

Hi, name's Sehaj. I'm in my first year of a Natural Sciences degree studying at the University of Leeds, England. It's a flexible degree with a masters option which I'm looking to take, perhaps gearing towards working in materials science. But I also have an interest in nanotechnology...

Let $A$ be the set of all positive integers $a$ such that $2^{2008}+2^a+1$ is a square. Find the smallest number of $A$ and prove that it is not the only member of $A$.

Hey everyone I'm new here but just about to start school again for mechanical engineering and was wondering what math would I need to take to lead me up to calculus because I've only passed one remedial math when I went 5 years ago

A pointer in C++ is represented by *. Sometimes the * comes after the variable/class/whatever such as 'Pointer*'. Other times it comes before, '*Pointer'. What is the difference between the two?What is the member access operator for? (->) According to my notes, a->b is equivalent to (*a).b

List the item you would most like to get rid of here on the PF faux auction. 1998 Yard Machines lawn tractor. Purchased new at Montgomery Wards. Mower deck is not included. This is the only lawn tractor that I have seen in an online auction that does not have a dead battery. Opening bid $600

Hello. I'm John, and I'm 25. Until recently, I was a part-time college student, and now I'm not. The degree I was going for, Computer Technology with a programming emphasis, was something I seemed to be proficient at, but it was also something that I have pretty much zero passion about. I...

Briefly, I need to design a framework which would support a plug which is used to fill in the hole in water tank, 4.8m above the ground. In other words, 10.69kN load at angle of 30 degrees is therefore applied to the framework. So I came up with my design. The problem is that I get zero value...

Homework Statement Determine the force in each member of the truss. State if the members are in tension or compression. P1 = 450 lb, P2 = 600 lb Homework EquationsThe Attempt at a Solution No matter what I try I get wrong answers. I need someone to get me going in the right direction.

Homework Statement Find the components of all forces acting on member ABE. Homework Equations Equations I used are on attachment The Attempt at a Solution I found moments about E and F. My reaction at E is correct. I just have a conceptual question about the reaction at C. The reaction is a...

Hi All, I just joined the forum and most of my inquires will relate to astrophysics. I am a retired professor of neurology and have turned my interests towards astrophotography and teaching astronomy at a local university. I have built my own observatory and my work can be seen at...

Homework Statement Homework Equations None given The Attempt at a Solution What I tried to do was figure out the force equations and moment equations, but maybe assuming that there is no moment nor net force is incorrect... I know I'm missing something here. I did an equation equating the...

I am going through Shigley's Mechanical Design book and have a quick question on fasteners. Sometimes when calculating the spring rate for a member, you have to multiply the rate by 2, why is this? For instance in this problem http://imgur.com/2ug9AaR When the spring rate is calculated for...

A family of functions is a set of functions that share one or more properties. ie: The family of quadratics with zeros 1 and 10, or the linear functions with a slope of 20. there is a family of linear functions where each member is its own inverse. What linear property defines the family? (I...

Homework Statement This crane lifts a 125 kg heavey motor. What is the member forces of BF and BD? Use 10 m/s^2 as accleration of gravity. https://dl.dropboxusercontent.com/u/11241083/problemtruss.png Homework Equations F=ma Sum Fx=0 Sum Fy=0 Sum M=0 The Attempt at a...

Homework Statement Homework Equations qs1(0)=qs3(5) qs2(0)=qs1(5) qs3(0)=qs2(6) Vy=0 q(s)=-Vy/Iyy*Q(s) Where Q(s)=y*A Where y=y coordinate of centroid and A=Area The Attempt at a Solution To be honest I'm not sure how to separate the q(0) term, nor do I know what the...

Can somebody help me with this problem? I have to proof if 41/81 is a part of attached sequence. Step by step guide would be useful. Thank you! http://img.tapatalk.com/d/13/10/18/2unyje8y.jpg

Hello, When given a truss structure, how does one tell visually just by looking at the structure which members are zero force members?

http://i1341.photobucket.com/albums/o745/nebula-314/20130909_125150_zpse5d4c881.jpg I am not sure how to go beyond this point or even if I have the compatibility problem correct, I am assuming that the bar does hit the other side of the wall. But when I go to solve this I have to many...

an(n in subindex)=(1/2)*n^2-3n+5/2, when n ≥1 Is number 10 member of that sequence? what about number 6?Create equation to solve it. If someone can help with this problem please, it will be much appreciated!

Hello, I just happened upon this forum, and I have to say it seems pretty amazing all the topics it covers, from homework help to specific forums for engineering and math, I wish I had found it sooner! I already know this will become a useful resource for me. Unfortunately, I already must...

Does anyone else here have a family member with a mental illness? I have a family member (Bob) with schizophrenia. Bob was diagnosed about 4 years ago. Since then it's gotten progressively worse. Bob can't hold down a job and lives off social security. Lives in a shanty apartment. Bob dropped...

Attached is a picture of the truss. I am trying to calculate the member forces. I know a moment is = force * perpedicular distance, but in this case, for example, if i am taking moments about A, Would the equation be -(1*2KN)+(1*c) = 0 or using an alternative perpedicular distance...

Homework Statement Determine the zero force members in the following truss Homework Equations - If only two members meet in an unloaded joint, both are zero-force members. - If three members meet in an unloaded joint of which two are in a direct line with one another, then the third...

Homework Statement I meet a problem below: To check if the angle :200x150x12 S275 Grade can take a twist of 30kNm (on plan ) with Span 3m fixed end connected. Homework Equations θ = T L / J G The Attempt at a Solution My question is that even I got the angle of twist for this...

Homework Statement The diagram is attached. I must solve using method of sections the force in member HG. Homework Equations ƩF(y) = 0, ƩF(x) = 0, ƩM = 0 The Attempt at a Solution My hand-drawn pic shows the section. Solving vertically, ƩF(y) = 0 F(DG)cos45 = 10 F(DG) =...

Homework Statement Let A be an n*n matrix and let B be a real number, Nothing which properties of matrix multiplication you use, show that the set W= {x member of R^n | Ax=Bx} is a subspace of R^n, where x in the equation Ax=bx is represented by a column vector instead of an n-tuple with...

http://imageshack.us/photo/my-images/853/bridgel.png/ I don't answers course just some guidance. I need to find the forces at each joint, and stresses inbetween too. I've calculated the reaction forces by taking moments as 779N at far left and 692.5N at far right. Now I'm using trig of...

My apologies, I don't own a scanner or else I would show the 200 variations of formulas I've played around (my work) with all day to get these answers. Question is this; A short compression member is fabricated from 2 steel pipes. the pipe on the top has a cross sectional area of 3.17 in sq...

Homework Statement Determine the force in each member of the loaded truss. The force is positive if in tension, negative if in compression. I have attached an image of the problem Homework Equations The Attempt at a Solution I defined the positive y-axis to be from B to...

Homework Statement There are two groups, group 1 and 2. Group 1 has a 0.5 chance of losing $36, while group 2 has a 0.1 chance of losing $36 dollars. The groups are of equal size. Now an insurance company is willing to cover the losses for a payment. However, the insurance company has an...

Homework Statement I am trying to allocate memory on the heap (free-store) for an array of characters using one of my struct members, which is a pointer. However, I am running into scoping issues no matter how I try to go about doing it. Homework Equations <data type> *<pointer name>...

I know we do the Member Awards every year in Nov/Dec, but what are your thoughts for a "silly" awards list? Things like: Most times slapped with a mackrel. Most times almost banned by Evo. Easiest avatar to make fun of. Longest forum post that completely misses the point of the...

Anyone interested in following LQG research may wish to listen to Frank Hellmann's talk. Download the slides PDF first before starting the audio. He will say when to advance to the next slide as he goes thru the talk. This gives a clear concise overview of a reformulation of LQG led by Bianca...

Homework Statement Figured it would be easier if I showed a picture http://img210.imageshack.us/img210/707/problemcz.jpg Homework Equations Ʃm=0 Ʃfx=0 Ʃfy=0 The Attempt at a Solution Here is my attempted solution, I am missing member BD and not sure which way to solve it, I...

Hi all, i have been a member of a few IT and hacking forums but they always get full of arrogant little kids who seem to have nothing better to do than to wind me up. Then I found this place, by no means am I a physicist (got A* in science GCSE then joined the army...) however I am hoping to...

Homework Statement see attachment Homework Equations The Attempt at a Solution The book says the strut is a two force member. Why then isn't there a equal but opposite direction force Fba at point B? Isn't that what a two force member means? Why for this two-force member only the force at...