Lab Definition and 1000 Threads

I'm doing a physics lab right now and to find tension we use the equation T=m(g-a) where m is the suspended mass and t is tension. I'm not sure if g should be negative or positive. I'm guessing negative but I am not to sure.

Hello. I am performing some biochemical process where the end product is going to be intended for human consumption. I am curious where I can buy large quantities of ethanol that is safe for drinking. I don't want to use the liquor store corn alcohol because it has some impurities...

Homework Statement A 4.5 kg block is on an incline with a coefficient of static friction of 0.50. The angle that the ramp makes with the horizontal is increased gradually, until the block begins to slide down the ramp. If you know that the coefficient of kinetic friction between the block and...

Hello, I recently did an experiment of nanoparticles (specifically Au Nanoparticles) We did the Turkievich method and the borohydride method) for the turkievich method we got good results and this is indicated by the UV spectrum of the sample.. for borohydride though... we got a...

I'm starting on physics I (introductory classical mechanics) and although I love the theory class, I find the lab extremely tedious and tiresome. I'm just two experiments since starting (we've seen grafication and measurement uncertainty) and they are quite disencouraging, specially after...

Homework Statement Calculate the acceleration of a ball rolling down an inclined plane and also note the error. I am going to solve it myself, so I will just give one sample. Distance covered by ball(error : +- 0.05 cm) .95m Time taken(error : +- 0.01 s) 1.19s Acceleration(with error)...

Hi there I need help with my lab to solve motion equations using Newtons law Basically I did my experiment based in projectile motion, one of the trial give me 88cm out of the ramp, like distance traveled, then the total horizontal length of the ramp was 111.5cm and the height 40cm, also the...

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12517.html

hello everybody i want to setup up a computer lab for a school as my ngo but i still don't know much about servers and i was hoping i would get some help here

I'm curious? Do you prefer analog? Digital? No watch? Any specific brands or features you wouldn't wear a watch without?

Sure we all know it happens at the core of the Sun, but the half life for a proton there is a billion years because p + p -> D + e + v is so unlikely A thermonuke bomb using light H would give no extra energy at all above the fission primary. Even the Sun only gives a few watts for bomb...

Hey everyone, I'm wondering if, as a physics major, I should take labs with all of my other science classes as well? I'm taking a one year sequence in general chemistry over the next two semesters, which has a mandatory lab component. My main question pertains to biology. I'm going to be...

In QFT equations, there are not only positive energy solutions, but negative ones as well. Dirac had the hole theory. But the sea may have infinite charges and gravity effects. And then QFT textbooks just explain the negative solution as anti-particle. But in the lab, we measure the...

We have a small lab reactor (~2 Litres) made of stainless steel that we use to test reactions. Unfortunately, we now have one test which has a hot acidic environment (dil. HCl approx. 20%) that would corrode the native stainless steel. Is there any way to work around this? Maybe a...

Hi all Last week i had an exam in electro-optics lab. we were given a question in optical Fourier setup (attached) and then we have some questions about the purpose of the setup. I claimed that the aim of the proposed setup is very similar to 4-f system for inverse Fourier...

Hi everyone, I am having some trouble and I really hope someone here can point me in the right direction. I have been following this wikihow: http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply. In general, my power supply seems similar, although the coloring...

1. This lab is based on 'Newtons cradle' () I can't link to the actual lab video because that requires my password and username...not that I don't trust you guys/gals but its a public site. Anyway, he let's the first ball go at 3.0 cm above it's equilibrium position and asks for me to calculate...

Is that weird? I live in apartment, so when I order stuff from Amazon, they just leave the stuff in the foyer for anyone to pick up on. Maybe I could just send it to my "office" at "work?"

Hey, I just came across this idea that sounds really cool in theory, but I'm wondering if anyone out knows if it's actually technically possible: Lab-on-a-chip detectors http://marblar.com/challenge/Micro-mixer/idea/1237 So the analyte is passively mixed by a tiny microfluidic mixer which...

Hi all If I want to volunteer in the research lab in the summer, how should I contact the professor to inquiry about this opportunities? I am an undergraduate electrical students, and I am interested in the the signal processing and data communication. However, I don't have any related...

Hello, I was competing calculations for a simple machine lab, and I got a different mu_k for 3 separate inclines of 20,30 and 40 degrees. But a question asks says ,"explain why the coefficient of kinetic friction should be independent of the inclination angle of the inclined plane." How do I...

Hey PF, quick question for you guys. I got offers (on the same day!) to work with a professor at my college (1.5 hours away from home), paid, to do some experimental work. I also was offered an internship at the Naval Undersea warfare center in Newport, RI (~40 minutes from home). I will be...

Hey! I'am doing a X-ray spectrometer lab, need some help regarding the absorption of x-rays by matter. one simple question, does material with higher atomic number stop more x-rays? I have following measurement values: no filter, 6k impulse rate/s 50 Sn, 111 impulse rate/s 30 Zn, 3173...

Hello I am a undergrad electrical engineering student. I took two courses on C before. With C, this seems to be not enough because I am hoping to help out in some engineering related research project at school. Currently, I have no idea what type of research I am looking for. I am just...

Homework Statement Hi, I had to calculate the charge of an oil drop using a lab simulation Homework Equations q = mgd/v The Attempt at a Solution This is the result i came up with: The charges are not multiple of 1.6x10^-19 C. How can i fix this? Thanks

Hi all, What is the highest frequency photon ever seen, whether in nature or the lab? This is based on an earlier post of mine, but I think has merit as its own post. Since E=hf, there is no maximum freq or energy of a photon, it seems, on a max freq of a photon. It seems that such high...

If an object of mass M falls under the influence of gravity and a drag force Fdrag, we may write Newton’s Second Law as Ma = Mg - Fdrag Where a is the acceleration of the object and Mg is the weight of the object. The drag force has the general form: Fdrag = bv^n Where the drag...

Homework Statement Our professor makes us design our own lab. For the lab we have unknown resistors, capacitors and inductors. Using an oscilloscope, function generator and some wires we have to figure out what the values are for all these elements. Homework Equations The Attempt...

I am currently taking a quantum physics lab. The results from my most recent lab are troubling me. A quick description of the lab The setup includes an incandescent light bulb which feeds light into a monochromator. The monochromator consist of a couple mirrors and a diffraction grating. The...

I have the following process: two ingoing particles, a photon hitting a nucleus, and two outgoing particles, the nucleus and a pion. I have computed |M|2 and the differential cross section in the center of mass frame dσ/dΩCM; I now have to go into the lab frame, where the nucleus is initially at...

Hi, I have to do a lab simulation and fill out information in a chart. The lab simulates two pucks hitting with each other. It is suppose to be a momentum lab. I have filled most of the chart but am not sure if its correct. So I would like you to verify it. Plz and TY These are the only...

Homework Statement Calculate the theoretical yield of the isomers from your data. Note: Find the limiting reagent. List of Masses I obtained during lab: Maleic Anhydride (C4H2O3): 5.05g, molar mass=98.1g/mol Impure Fumaric Acid: 2.28g Pure Fumaric Acid(trans-C4H4O4): 1.45g Pure Maleic...

Hi there; Right now I am currently in both a second level introductory college level Chemistry and Physics course. In chemistry, we have a semester project to do, and with a little physics background, we are going to create our own Ferrofluid. We need to figure out different things we can...

I hope this is an acceptable location for this post. Does anyone have any experience trouble shooting or access to a help file for the Tel-X-Driver and TEL-218DRV equipment? I have included a copy of my correspondence with the company explaining the situation below. Homework Statement My...

Could any here smart people help me with the Lab question: 3. Why do we measure the period by timing 25 revolutions? Why not one revolution or 100 revolutions? This is from http://www2.sunysuffolk.edu/denicog/labs/lab11_132.pdf Lab from Uniform Circular motion. Thank you so much!

so i have to do this lab for ib physics and i am a noob at physics and i am having some trouble with the lab that i have to do. Homework Statement the research question is "how does potential difference needed to operate an LED depend on the frequency of the light emitted? it is set up in...

I don't understand what this lab I'm supposed come up with will involve. There's going to be a sound generator producing sound waves. We will have a meter stick and a sensor to measure the sound intensity(W/square meters) and sound level(decibels). We will measure the intensity and level at 6...

Homework Statement The purpose of this experiment is to measure the smallest unit into which electric charge can be divided, that is, the charge of an electron e. The method is the one proposed by R.A. Millikan in 1910. A small sphere of mass m having a charge q can be suspended in air by...

Homework Statement Calculate the initial velocity at which water exits the spout of a common drinking fountain Homework Equations V1x=V1cosΘ Θ=tan-1 (opp/adj) V1y=V1sinΘ V2^2=V1^2+2ad The Attempt at a Solution I measured the total distance traveled by the water in the...

Hello, I am currently working on my lab, and am wondering if someone would be so kind as to give it a gander. The only section I need looked over is the theory section, which, incidentally, is the only part I have written thusfar. I'd really appreciate it if you could critique the theory...

Hello, We are doing a lab studying terminal velocity. Unfortunately we do not have a motion sensor, so we are dropping coffee filters at a certain height (both scrunched and flat- while increasing their numbers), and noting their final speeds. The thing I don't quite understand is whether...

Hello, I am stuck on the last page of my physics post lab. The lab was on elastic, super elastic and inelastic collisions. The point of the lab is to see whether or not momentum and kinetic energy is conserved during each scenario. I'm pretty sure that in the elastic and super elastic...

Hello, I have been stuck on this prelab all day.I have finished all the questions except for the last one, where it asks you to find the uncertainty (or standard deviation) of Fave. I have tried every resource and nothing has helped so far. Any help would be great! Thanks

Homework Statement I've attached the lab sheets for the lab I am currently working on, and I am wondering if someone could help me with it. Homework Equations The Attempt at a Solution I am having difficulty with part two, steps 5-8. I have the slope from my excel graph 0.6458...

I will be treating carbon in 3 steps under reflux and I would really appreciate some suggestions, tips and advice on getting a proper and SAFE setup in the lab. I have at my disposal a fume hood and standard laboratory glassware. Treatment 1: 20g carbon treated with 100mL 65% Nitric Acid under...

Duct Tape Challenge In this lab you and your group members will duct tape one of your members onto a wall using ONLY duct tape. The purpose of this lab is to understand forces and how they work. The rules for this challenge are below: • Each team consists of up to four team members • All...

Homework Statement 1) Why does the centering ring not start to shift as soon as you change the angle? Homework Equations none The Attempt at a Solution 1) It does not shift because the equilibrium of the resultant vector can vary from -1.5 degrees to 2 degrees based on our data.

In my introductory physics class in high school we did a lab on specific heat. We heated metals and placed them into cool water and observed the temperature change to find the specific heat of the metal. One of the questions on the lab puzzled me. - Why was the cool water purposely...

Homework Statement Use the circuit shown to answer the following questions. At time t = 0 the switch in the circuit is closed. Answer the following questions after the switch in the circuit is closed. What is the equivalent resistance of the circuit given R1 = 5 , R2 = 5 , R3 = 4 , R4 =...

Hello, I am stuck on this post lab question. I have tried to answer questions 1 and 2 but I am unsure of my answers, could someone verify them to make sure I did this correctly? Also, I have no idea how to do number 3! I included screen shots of the problem. Thanks very much.