Hi Definition and 291 Threads

Hi Team... Hope you can help me as I'm sooo confused right now. I've only been doing Math for about 4 months :( Any direction as to how to start solving this problem would be amazing...Fire Rescues Fire trucks with extension ladders are used regularly to remove people from burning buildings...

does glucose in its cyclic structure react with HI to form CH3-CH2-CH2-CH2-CH2-CH3? (open chain structure of glucose reacts with HI to form CH3-CH2-CH2-CH2-CH2-CH3)

Homework Statement What would be the effect of calculated value if: a. Jockey weight is in error by 1 g? b. Distance from vane center to pivot point is in error by 1 mm? c. diameter of nozzle 0.1mm different from actual nozzle diameter. Homework EquationsThe Attempt at a Solution as the error...

I'm Daniel, newly subscribed to the forum, although I've been reading some posts during the last month. I want to improve my knowledge in physics, specially, quantum mechanics, and, I know I can find help here. In addition to this, and, as English is my third language, I know I can improve my...

Homework Statement Lawn spheres placed on pedestals are convex mirrors. One such sphere has a diameter of 40.cm. A 12 cm robin sits in a tree 1.5m from the sphere. Make a representative sketch. Where is the image of the robin? How long is the robins image? Homework Equations...

Hi everyone. I am self studying for my GCE for the past 6 months now. I have been doing revision for a long time and did some question papers. I have a few problems and hope the people here can guide me. Thank you Problem 1. Homework Statement A 5.0kg mass is suspended from the ceiling. A...

Hi, At present, I am learning about Switched-mode power supply and Low drop out regulator using CMOS. Could anyone suggest some good books about this? The main problem here is "using CMOS". Thanks.

I just turned 16, am in 10th grade, and am new here. Long story short, my father teaches AP Biology, AP Chemistry, Anatomy&Physiology, Astronomy, AP Biology, and AP Physics, and is middle school teacher. He's best known for his successful passing rate. Well, I took his class for AP Bio in 7th...

Hi all, it's been awhile since I've been to PF. I just got an automated email from this place imploring me to come back, and I remembered all the good times I've had here in the past. A lot has happened in the past couple years (or however long it's been since I was gone). I've done a lot...

A high Q antenna basically means the antenna stores a large amount of energy in the near fields compared with the electromagnetic energy radiated per cycle? When the alternating current momentarily stops in our half-wave antenna charge density is maximum at the ends of the antenna, and the...

hi! actually, I am doing my computer science engineering...and i don't have more knowledge about electronics... all i need is to know is how a usb host controller works...and how can i make on my own... so that i can connect any USB devices on it ...and use it...

Just popping back in. Every now and again I think about where I was 8 years ago and where I am now. I don't want to sound like I am tooting my own horn, so I will skip the details. But I know that I own a great deal of gratitude to PF and its unconditionally supportive community. And also to...

Hi! i want to calculate the Rinput and Routput of this Active Filter. How can i do that? "][/URL]

Hi, I'm new to this forum and I could use some help. I'm a freshman in high school and for a school project, we have to make a magazine. My group and I are doing a tech and general science magazine. I'm writing a feature story on metamaterials, and a future where they are abundant. We need...

Hi everyone. This isn't a specific homework problem, I'm just trying to understand a concept. I've been studying the HI profiles (from the 21cm emission line). Almost all of them look like the attached profile. The velocity on the x-axis corresponds to the amount that the line has been...

Hey people! My names Josh and have always had an interest in the natural world, physics, and most especially, astronomy and all its related fields. Unfortunately, it stopped there and remained simply as an interest, mere dabblings in fields of knowledge that I really had no comprehension of...

Hi, I'm Adrian, a British student at college (US = senior high school year I think) studying Advanced Levels in maths, further maths, physics, chemistry and economics. I plan to go on to do Physics BSc at university hoping for either Oxford or Durham universities (depending on my grades this...

HI, I'm new:) Hi! How are you? My name is Ty & I'm an EE student from Minnesota. Thought I'd introduce myself because I'm here for the long haul! Here I am, My first circuit, & this is why I love engineering, ^That feeling... Heading up to my 1st arduino meeting tomorrow. Super...

This is coming from my (just graduated) High School perspective (also my first post :blushing:) I'm interested in Biochem but want to know about atomic/particle physics. I mean I'm interested in biochem because I want to (for a lack of a better phrase) be part of drug discovery the...

Hi guys, I am sure you receive hundreds of posts like this all the time so please be patient :). I need to apply for university and I'm very lost. Originally I was thinking of doing Math and Physics but then my brother (an E. Eng.) confused me. He says that since Eng. is so similar to Math &...

Hi there. Just looking at an astophysics journal article in which they say the temperature of a pulsar is T=300eV.. My query is the following: is T=300eV shorthand for say T=300ev/k (k=Boltzman constant) so the corresponding temperature in Kelvin is T=3.75X10^6K?

Hi all, Im having a bit of trouble understanding the concept of viscosity in the scenario of a fluid between two plates, with one moving and one being stationary: what is the relevance between the viscous force of the fluid and the shear stress on the fluid given by mu(du/dy) ?

HI I'm new here. I've been having a little bit of trouble with a few of my physics problems. It seems like very basic stuff. I went to my professor's office hours and he didn't help me. He told me the wrong stuff, and when I emailed him back, he said different stuff. 1) An ideal monatomic...

I am new to this site and have forgotten so much of what I have seen in the forums. I hope to be able to use the problems and solutions posted to help me to relearn the higher level math and physics I have forgotten. I will add that it is true that when you don't use it you lose it. Having gone...

Hi This is a really trivial comment in my notes but for some reason I'm not seeing it... The following image demonstrates the perpendicular distance from an origin to the line of action of the force given as x*sin(x,F). So the moment, M = f*x*sin(x,F) which I understand. But why is it...

Hi folks I am currently doing a question in fluid mechanics and i need some help rearranging formula to solve the equation... I have everyhting i just can't seem to figure how to make u( Velocity) the subject of the equation... The equation is μ = Fx/uA Thanks in advance Eddie

This is my second year of college, but my first year of EE (just decided that was the major I wanted.) In addition to a gen ed class (american government) and math classes (calc 1, and stats 1) I have a couple of EE classes, but I have no idea what to expect. I was hoping maybe some of you...

Hi,I m trying to find out,what is imaginary unit/number.How to imagine it.I was reading many articles and analogies,but I still have some questions to get better idea what is it.So I m going to write some points,that are mystic for me. My question is maybe more philosophic than mathematic...

Hi I'm white knight(night) and I'm from california. I noticed you didn't have a new member intro section, nor an off topic section so I'm posting here. I signed up on your forum because, well to be frank, i had a bad trip on some drugs about a year ago and had a psychotic breakdown/shift in...

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...

Hi ,i need books, sites... about Mindlin's Theory for thin plate Hi , i need books, sites... about Mindlin's Theory for thin plate (Vibrations). Thanks pmcr

Hi there I've finally decided to sign up after this site has helped me hundreds of times with my assignments and other uni related questions. There is always something off here that comes up in my google search results :D Anyway just thought I'd make an intro post so it doesn't look like I...

Hi my names DocHoliday. I see how many very insightful and well written pieces you guys have had on numerous problems and thus have decided to join the forums. A Large Thanks to the whole community is in order as you have helped me through a few things without me even being a member! I'm...

Hi, new forumer here. I've found this site a couple times before from google searches and whatnot but I've always been too scared to post here as everyone seems much too intelligent for my questions. However I can't find a decent answer to this question, perhaps there isn't one, however...

Hi is light a kind of acceleration? (not velocity or momentum)

hi guy i have a question regarding digital fundamentals plss help:))) Show how ONE XOR gate can be replaced by THREE 2-input logic gates.You are allowed to use any logic gate except XOR and XNOR logic gates...anybody can solve this?:))

Hi, new to the forum. Great place but much of the info far past my interlectual understanding. :frown: I have been looking at the idea of an induction heater for use in my job. I'm a mechanic by trade, nicknamed proffessor screwtop by my workmates :) Snap recently introcuced the...

Hello everyone. okay so here is my situation, I restore my home computer of windows XP. now that i have done that, it is telling me i can't download anything becuz of a .net passport from msn. i signed up for a LIVE account for it, and i re-did the .net passport thingy, so when i entered...

I am Kimberly, newbie here. I love here!

Hi every one, My question is what should be a pressure in a open end tube,in which one end is connected to a pump and the other end is dipped in a liquid container. the pressure of the end which is connected to the pump. thanx. if some one has some idea. working. My view is the pressure at...

(No, I'm not 13!, I'm 13. I am not THAT old) Hi! I'm not sure where to put a "Hello" message, so I suppose here will do. Great to be here. Before you think "GTFO 13 year old", I love Complex Numbers (I prefer "Complex" to "Imaginary" because "REAL" numbers are actually figments of our...

Hi, I wanted to know the following: Input Supply: 56KVA @ 220-240V (Municipal Supply) Required 1000Amps @ 220-240V Can a Transformer be bought to step up and supply the required power.

hi every body, I'm working and calculating the keff, and total hi every body, I'm working and calculating the keff, and total fission produced in critical accident in the cylindrical model. If critical mass is roached. I calculated variable multiply coefficient (keff) by MCNP 5. also [B]total...

Hi guys, I am having some doubts getting this exercise: 20,0 g of iron (60% purity) are reacted with sulphuric acid (80 % pure) Iron (II) sulphate and hydrogen are formed: Fe + H2SO4 → H2 + FeSO4 1. Which is the limiting reactant? 2. How much Iron (II) sulphate will be obtained? 3...

Hi all, I have a 90kva 3 phase 440volt/220volt stepdown transformer. When i test on no load ie secondary not connected to anything but the power is on, i get 220v between phases but to Earth or ground i get 1st phase 150volts 2nd phase 104volts 3rd phase 150volts Does this mean my...

Hi, I am currently doing a project to design a lamp and am really interested in using physics to gain a perfectly balanced design. I have come across this diagram... http://upload.wikimedia.org/wikipedia/en/a/a7/Lamp_2_counter_weight.PNG I just want to clarify a couple of things before I...

Hi there! So i have a q from the realms of thermodynamics , should be simple for you guys because I'm' in high school. So ,i stumbled over a problem(NOT HW POST) and the text was rather interesting it said that in a vessel from which the air is quickly evacuated contains water at 0 Celsius,now...

Hi. I'm testing a PMT and I'm surprised by the following. With power supply (-900v on K) and with no charge between output electrode and ground, I measure -126 V same with scope (Zin = 1 M) or DVM (Zin = 10 M). I must precise that this experiment has be made in a room not completely dark. Can...

Hi there, To find the gradient of a curve, we draw a chord on the curve and then makes the 2nd coordinates ( B ) tends to A ( 1st coordinates ). To find the gradient of the chord, i.e, ΔY/ΔX, we replace the two coordinates into the equation of the curve. But my question is why do we...

Hi all I want to read more on wormhole theory and create speciality in wormhole theory . I am from engineering background, working in IT industry. so totally out of touch with physics and mathematics.Can anyone suggest some road map for me. How i can grasp the intricacies of wormhole theories.