Practical Definition and 308 Threads

  1. P

    Lab Practical Circuit. Find Unknown Resistance.

    Homework Statement So I have to wire the circuit and find R2 by only making another voltage measurement. We know that R3 is equal to 1000 ohms. Homework Equations The Attempt at a Solution So I was thinking that you can find the voltage of R3 and the find the current going...
  2. AGNuke

    Practical Organic Chemistry - Confirm positive test

    I don't know where to ask this question, but anyways, since it was asked in an exam, so finding out the correct answer afterwards is a moral responsibility as a homework. So here I am. My question is whether the compound 2-Hydroxy-5-nitrobenzaldehyde (Did I named correctly?) gives positive...
  3. S

    Ohms Law and Its Practical Limits: Investigating a 10um Steel Wire

    Does Ohms Law have practical limits? For example:A piece of steel wire of length of length 10um and of CSA 20E-10. Can we calculate the resistance of such a tiny piece of wire (resistor) in the usual way? thanks
  4. M

    Practical implementation of focused UV laser

    As a quick heads up, I'm buried over my head in an imager project, and the portion that has given me the most headache is the UV source. Essentially, I need the source to make nice little 13 micron dots in the 405 nm range. I've been assured by a pair of vendors that this is an easy matter...
  5. M

    Practical Applications of Magnetic Monopoles: Possibilities and Limitations

    I'm not a professional in any scientific field just an avid consumer of popular science writing. I ran into a mention of magnetic monopoles awhile back and have been trying to dig up the answer to a few questions. Thus far I have failed so I decided to ask here. OK I understand magnetic...
  6. L

    Physics Is a Career in Astrophysics Better in Instrumentation or Theory-Computation?

    "Practical" astrophysics. Hi, just a lowly undergrad hoping for some of the wisdom here to rub off. I have always had a keen interest in astrophysics and have considered giving a colder look at long-term prospects for an academic path in theory/computation in said field. Long-term stability...
  7. P

    Finding Input/Output Impedance of a CE Amplifier: Practical Methods

    how can i find input and output impedance of a ce amplifier- (voltage divider )..suggest practical methods?
  8. M

    Is there a practical way to make homemade 3% H2O2?

    Dear all, Just as the title says - is there a practical way to make homemade 3% hydrogen peroxide? I'm looking to move to a remote section of Texas where medical help may be hours away and I know how H2O2 can prevent serious infections and has other medical purposes. Any help is...
  9. narrator

    Practical Cosmology: Examples of How it Helps Our Ventures

    Not sure if this is OT for the cosmology forum.. pls move if so. I'm wondering about examples of where cosmology science has helped in a practical way. Not being facetious.. genuinely curious (and I think knowledge for knowledge sake is almost always a good thing). Cosmology has helped...
  10. C

    Find (practical) current source constants, I and R

    Homework Statement A practical current source has a current of 22 A. Loading the source with 50 \Omega results in terminal voltage of 390.3 V. Obtain the source constants, I and R.Homework Equations V=I\times RThe Attempt at a Solution In my clumsy picture below, shouldn't I_{load} be replaced...
  11. C

    Practical real world uses for Colorimetry

    I need to give a short presentation about Colorimetry in my chemistry class. I plan on using the first five minutes giving an example procedure about determining the concentration using MicroLAB's spectrophotometer hardware in our lab. I would like to use that last five minutes of my...
  12. B

    A practical question from a resident in Tokyo

    I discovered your site yesterday, and have been fortunate to find such fine quality and detailed information on the Japan situation. Forgive me if I missed this already, but I have a few questions on actually living in Tokyo - I would much appreciate any responses: 1. The radiation level...
  13. O

    Need help with a physics practical to do with slingshots?

    Need help with a physics practical to do with slingshots!? Basically I am doing a project on slingshots, we are allowed to investigate any areas do do with physics, however I need some ideas, I was hoping I could change a couple of variables and measure things. my idea was to change the...
  14. O

    Need help with a physics practical to do with slingshots?

    Need help with a physics practical to do with slingshots!? Basically I am doing a project on slingshots, we are allowed to investigate any areas do do with physics, however I need some ideas, I was hoping I could change a couple of variables and measure things. my idea was to change the...
  15. D

    What Are the Practical Implications of Limits in Scientific Research?

    Hi can you please tell me the practical meaning of LIMITS...?
  16. R

    Can you help me prepare me for my E&M lab practical?

    I have to perform a "lab practical" tomorrow for my E&M class and it involves using a multimeter to determine what is inside a "black box" - either a battery/resistor combo or a capacitor. Homework Statement Taken from the lab practical write-up: "You’ll be given a box with two...
  17. Y

    Where Can We Find Limit Cycles in Practical Machines?

    Where we can find Limit Cycles Phenomena in Practice, I mean in which class of machines?
  18. B

    Inductors and magnetic cores anyone? Practical problem

    Hi there! So here's the deal. I'm restoring a friend's old Philco radio for his 1968 Mustang. This includes changing out the internals to tune FM instead of AM. The old AM internals include a set of three inductor coils with magnetic cores that move in and out of the coils as you turn the...
  19. T

    I want to be practical but it is so boring

    I am a high school senior preparing to choose what i shall study at a tertiary level. For many years i have had an interest in mathematics and theoretical physics. When i was younger i read brian greene, hawking and Randall. Yet i am now well aware that the theoretical aspects of science are...
  20. H

    Hot air gun, practical use of Faraday law

    Hello, I have the following question, I am trying to build a home made hot air gun for electronics soldering, my approach was with a modified Microwave oven transformer, multifilar 12mmxmm copper cables, and a 15cm stainless steel tube, the air is pumped from a powerful aquarium air pump. The...
  21. V

    Help for Physics lab practical?

    Hey all, I'm trying to prepare for an upcoming Physics lab practical, but I'm having a hard time trying to figure this thing out. I'm not a Physics major, and I really don't have the "eye" that some other people have on what comes to Physics problems. I'm hoping that somebody could help me...
  22. M

    Practical use of binomial and Poisson Distribution in the field of engineering

    Hi... Hope i 'll get the good result that where we practically use the binomial and poisson distribution in the field of engineering...
  23. B

    Rolle's Theorem: Practical Applications

    Homework Statement I know that Rolle's Theorem states that if the function f is continuous on the closed interval [a,b] and differentiable on the open interval (a,b), and if f(a)=f(b) then there is at least one number c in (a,b) such that f'(c)=0. I want to know if there are any practical...
  24. S

    Is Digital Image Processing practical outside academia

    I need to take one more course for my EE Bachelors degree in one of three specialized areas: Signal Processing, Controls, or Communications. I know all three of these are very much related, but I am finding Signal Processing by far the most fascinating field out of the three. The problem is...
  25. B

    Practical limit on Resolution (Diffraction Grating)

    Homework Statement In order to increase resolution of the diffraction gratings we can use them in higher orders of diffraction. What is the practical limit on using very high orders of diffraction? Homework Equations R = \lambda / \Delta\lambda = Nm The Attempt at a Solution I...
  26. J

    Practical control parameters for UAV?

    Hi, Anyone has had experience with UAV control/signal design can tell me what is the typical flight speed (surveillance UAV), control range, link speed and control delay like? (Sorry, I am not a very good engineering student, furthermore control and signal not my discipline... I can only...
  27. Z

    Interesting practical question skydiving

    So I've read the highest skydive occurred from a balloon and the entire jump lasted on the order of 10s of minutes. Heres my question: How the do you know where your going to land? The Earth rotates at ~1000mi per hour that's 12 mi per minute or 2.7 miles per 10 secs. So did these people use...
  28. S

    Practical question- anyone w. experience w. BBO crystals?

    hi all- having a strange (perhaps expected?) problem inserting a BBO into the optical path of a TiSaph fs laser. the issue is that i can achieve strong SHG output, but only with *severe* spatial distortion of the pulse shape. has anyone had experience/encountered this issue in an...
  29. P

    Practical Report For Investigation to flight (wind tunnel)?

    So we need to make a practical report and I'm not sure how to do it. I've learned the basics like lift equals weight and thrust equals drag.. and then the teacher made a model wind tunnel in class, we then got air speed(km/h) and its mass(g) etc. for it then we had to convert them to life and...
  30. C

    Practical Problems Involving Differentiation/Integration/Limits

    Hi guys, As somebody who likes to learn and understand everyday problems I've really hit a wall... I learned differentiation, integration and limits in my undergrad course, passed the exams etc but the way it was taught was pretty bad, nobody ever gave us "real life" examples. Personally...
  31. Z

    Question on Practical Electricity

    Homework Statement [PLAIN]http://img186.imageshack.us/img186/6260/physicsquestion.jpg Homework Equations Not sure...? The Attempt at a Solution I believe the answer should be A or B. I'm thinking the live and Earth wires will form a complete circuit. Since there is very...
  32. R

    What Are the Practical Uses of Band Gaps and Free Carrier Absorption?

    what is the practical use of the concept of band gap other than classification between material? can free carrier absorption be manipulated by changing band gaps?
  33. N

    Practical approach to building a breeder reactor, help please?

    hi, i am interested in nuclear physics but i don't really want to delve into the complexity of it, so could someone please give me an idea of the practical approach to making a breeder reactor, i do not intend to build one, i just would like to know how i would do it if did want to build one...
  34. C

    What are the practical applications of the Gamma function in various fields?

    What are practical applications of the gamma function?
  35. L

    Physics Concepts in the Pendulum Practical

    1. The use of a flimsy retort stand meant that when the pendulum was in the motion the retort stand was also swaying slightly. Explain this. 2. p=mv, torque=rmg 3. I am a bit stumped on this one. My teacher suggested I look into the torque of the pendulum - the friction at the...
  36. A

    Ideal gas law practical application

    Homework Statement To measure how far below the ocean surface a bird dives to catch a fish, a scientist uses a method originated by Lord Kelvin. He dusts the interiors of plastic tubes with powdered sugar and then seals one end of each tube. He captures the bird at nighttime in its nest and...
  37. C

    What could be causing unexpected results in my magnetic circuit?

    Hello, I have designed a magnetic circuit.. C core with an air gap. I calculated the circuit as well as doing a simulation on it using FEMM software. The core is from 1018 steel. My calculation and simulation gave almost similar result.. So, there is no problem in my calculation or...
  38. S

    Protecting Telescopes from High Humidity: A Practical Solution?

    So, I just received my 3x barlow lens in the mail and let my scope sit outside for two hours to adjust..later I realize the humidity is 80-90% and my scope (6" dob) is literally dripping. Other than moving to Arizona, is there a practical solution to this problem?
  39. marcus

    Immanuel Kant on Supersymmetry: a Practical Evaluation

    http://arxiv.org/abs/1003.2967 Immanuel Kant on Supersymmetry: A Practical Evaluation Alexander Unzicker 4 pages (Submitted on 15 Mar 2010) "A short review of the motivations for supersymmetry in astrophysics and particle physics is given. Despite the amount of theoretical research...
  40. T

    Is it practical to make an electromagnet that causes a 200N force?

    I'm trying to construct an electromagnet that, when a loose piece of iron is inside the solenoid, will create a field that will attract that piece of iron with at least 200N of force. My thought is that I can fill half of the solenoid with an iron core, leaving space in the other half for the...
  41. T

    Teaching my boys practical electromagnetism

    I need help designing some build-from-scratch DC motors. I'm looking to build really robust motors that I can be be sure will demonstrate clearly the principles involved, but that can be modified by my boys and that they can really *play* with and use to run simple toys. I've already shown...
  42. J

    Practical possibility of Hawking radiation?

    i have long been a skeptic of hawking radiation. i would like to explore my concerns, and see what your reaction is. the concept hinges around the idea of a spontaneous particle pair being created somewhere near the EH of a BH. radiation would occur if one of the particles manages to escape...
  43. P

    A way to calculate the practical range of gravity

    Theoretically, the range of gravity is infinite. OK. But the nature of the fabric of space has "building blocks" (Planck volume?) So while a localized body of mass/energy distorts space-time, the distortion decreases away from the body. I would think this has a practical limit. Just as energy...
  44. N

    What to Expect for the Edexcel Unit 5 Practical Tomorrow?

    Unit 5 practical tomorow! Anyone doing the edexcel practical tomorow? I've been revising through past papers practicals, and saw some more on the edexcel website. I looked through and there are some things I'm hoping do not come up tomorrow - and there are not mark schemes to 3 of the older...
  45. P

    Is GPS the only practical application of General Relativity?

    I guess GR is also needed to accurately coordinate space flight, but I highly doubt without GR the space shuttle will have any problem finding its way back home. Gravitational lensing doesn't count as practical application. Maybe a subject with even fewer applications is quantum chromodynamics...
  46. C

    How Do You Calculate Equilibrium in a Tri-Level Mobile Physics Project?

    Homework Statement Well i have a lab practical due for physics and I am having trouble with it. we have to assemble a tri level mobile. that wasn't that hard. the difficult part is doing the math to support my answers. i need to use translational and rotational equilibrium. i looked...
  47. U

    Integrating 2^x: A Practical Guide

    Intergrate 2^x ... lol? How would I even go about this? This is not a homework question, but I'm practising for exams.
  48. M

    Practical questions on wireless internet bandwitdth

    (1) Sometimes I notice that the bandwidth goes up a lot after I start getting a large feed. Like, my internet might be going pretty slowly, then I start downloading a large file and my internet connection moves up to 24 or 36 Mbps, loading web pages very fast, despite the fact that I am also...
  49. H

    Calculating Load on Anchors for Three Hammocks

    Hello - I was wondering if anyone would help me with some calculations - using the diagram I have attached. We are trying to hang three hammocks from three achors - and would like some help calculating the load on each anchor. Even a best guess or ball park answer would be nice - or...
  50. I_am_learning

    How to Design a Solenoid for an Electric Door Lock Releaser?

    I am trying to make a an electric door lock releaser. I am going to use a solenoid to make an electromagnet that will pull down a handle to release the lock. The electromagnet has to act from a distance of 1 cm. And it has to impart a force of at least 10 N. The problem is to design the...
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