Measuring Definition and 1000 Threads

  1. K

    Comments on Double Slit Experiment for Accurately measuring distances?

    I'm thinking about using two slits, a webcam and a laser to calculate distances for a project. Usually you measure the distances between maxima but this can be easily measured in a dark room using Matlab and it's image processing routines. I can create the slits and accurately measure them...
  2. F

    Need Help - velocity measuring problem

    Hey i am doing an experiment for a school physics assignment on projectile motion. I have three variables which i want to change so i can see how i can obtain a maximum range (distance). I have chosen mass of projectile, angle of launch and initial velocity of mass as my three variable. My...
  3. D

    Can the LF351N op-amp accurately measure light intensity in a fish tank?

    Hello everybody, I am trying to measure the light intensity of light going through a plexiglass (U Shaped) in a fish tank using led. I would love to see accurate voltage measurements due to the change in the liquid level. I tried photodetecr transistors; it wasn't accurate at all. I am thinking...
  4. G

    Measuring the lifting power of an out runner motor

    Hi guys, how would one measure the lifting force that an electric out runner motor could put out. assuming one knows the rated power of the motor, how does one convert this into lifting force? Thanks, Ben.
  5. J

    Should volume flow rate measurements be corrected for different conditions?

    Hi I have a question about measuring volume flow rate with a laminar flow element. I read the pressure difference across the element (mmH2o) and I get volume flow rate (cfm) from a calibration law. If that calibration law was obtained at standard conditions, would I have to correct it for...
  6. I

    What is the most accurate method for measuring 6 mL of water?

    Can anyone please tell me which one of the following is the most accurate method of Volume measurement for 6 mL of water (density= 1g/mL): Graduated Cylinder, Pipet, or Buret. Also, how can you explain your answer. Every help would be appreciated.
  7. Y

    Measuring astronomical distances

    How do we measure distance to another galaxy without using the linearity of distance with red-shift?
  8. D

    Measuring Electric Potential of Monovalent Cation Solutions

    Hi everyone, The subject of this topic is what I am looking for. For example if the concentration of a monovalent cation in a solution is 1 mol/L, then how much is the electric potential of this solution? (This solution just contains one kind of monovalent cation and not any anion)...
  9. W

    Measuring Moment of Inertia of RC Helicopter

    Hi guys. I am trying to measure the moment of inertia of a remote controlled helicopter about its 3 principle axes at the centre of gravity. In all of the literature I have read relating to this project, everyone just glosses over this part. What I need to figure out is an experimental...
  10. M

    Measuring Specific Heat of Paraffin Using Cooling Method

    I am going my coursework. My aim is to determine the specific heat of paraffin using the cooling method. I was wondering what would be the systematics errors?
  11. B

    How Can I Measure Relative Amplitudes of Specific Frequencies in a Noise Field?

    I would like to measure the relative amplitudes (energy levels) of several specific frequencies in a noise field. I thought of attaching capacitive microphones to tubes that would resonate at those frequencies. I've visited hundreds of web sites that invariably give equations for...
  12. T

    What is the relationship between the speed of light and the meter?

    Since the question of units of measure has come up recently, I have a question... The length of the meter is derived from the speed of light. That is, it is the distance that light travels at speed c in a time period derived from the cesium atom. The speed of light is commonly defined as...
  13. L

    A rotating coil measuring the magnetic field

    Homework Statement A rotating coil is a common device for measuring magnetic fields. Consider a coil of area A and N turns that is rotated at angular frequency w in a magnetic field. The position of the coil is adjusted so as to produce a maximum induced current Imax which can be measured by...
  14. B

    Measuring resistance accurately?

    Homework Statement I was wondering what method is exactly more accurate. Would using an ohmeter, that is part of a multimeter set be more accurate than looking at the color code? My guess is that the ohmeter would be more accurate even though it is not a dedicated ohmeter, but I am not sure as...
  15. C

    Measuring angles using accelerometers

    Hi.. am doing a project to plot the path of a moving vehicle in a coordinate system using accelerometers. To do this, I need to measure the angle that the vehicle rotates when it's going on a road. (Note this is not the tilt) Does anyone know if and how I can do this using only accelerometers...
  16. P

    Measuring and container math problem

    i hv a question...? plis help me! a vertical container with base area measuring 14 cm by 17 cm is being filled with identical pieces of candy, each with a volume of 50 mm^3 and mass of 0.02 gr. assume that the volume of the empty spaces between the candis is negligible. if the height of the...
  17. F

    Measuring User Time and System Time

    Hi guys, I was wondering if anyone has a simple program (they can post) that can measure the User time and System time used by a program, or what library will be useful to creating this program or function? Thanks, Ed.
  18. B

    Measuring work using elastic system

    I have built an apparatus that is intended to measure external work output. It consists of force transducer connected inline to latex elastic tubing stretch to ~twice it’ resting length (via three pulleys) connected to a linear variable differential transducer (to measure displacement) connect...
  19. K

    Measuring Magnetic Moment of a Torque Rod

    Hello everyone, I am working on producing a torque rod (basically a solenoid) for use in a spacecraft that I am working on here at University of Colorado, Boulder. My requirement for this torque rod is to produce at least 7.7Am^2 of magnetic torque. Currently, I have made a torque rod...
  20. L

    Frustrated with Physics: Measuring Temperature Changes in the Ocean

    Ok. At a depth of 1000m, the ocean temp is 4 degrees celsius and the speed of sound is 1480m/s. From lab experiments, for every 4m/s increase in velocity, the temp increases by 1 degrees. When the distance is 8000km, the smallest time change that can be detected is 1s, what is the smallest...
  21. D

    Measuring Energy and Linear Momentum Consecutively

    Problem Can the total energy and linear momentum of a particle moving in one dimension in a constant potential field be measured consecutively with no uncertainty in the values obtained? Solution Yes, this is possible. The energy and linear momentum operators are, respectively \hat{H} =...
  22. D

    Measuring Quantum State: Solving for a Specific Value of a Unitary Function

    The other thread was going too off-topic, so I'll repost here. Why is this not possible, without considering FTL signals?
  23. R

    Penning Measuring gauge configuration

    We use, among others, Penning pressure gauges for determining pressures (aprox. 1E-7 to 1 mbar (about the same in Torr... for the Americans here ;-) ). The Penning is placed just outside the recipient, behind a valve to make sure its never in pressures of 1mbar or more. When using a smaller...
  24. H

    Do Moving Train Tracks Appear Shorter Due to Length Contraction?

    Apparently a moving rod shrinks. What are the measurements of two moving parallel train tracks?(2 vertical tracks moving horizontally)
  25. H

    Measuring the moment of inertia

    Homework Statement You are asked to measure the moment of inertia of a large wheel for rotation about an axis through its center. You measure the diameter of the wheel to be 0.740 m and find that it weighs 280 N. You mount the wheel, using frictionless bearings, on a horizontal axis through the...
  26. R

    Measuring Potential Differences in a circuit

    Is there anyway of measuring the potential difference between 2 points on a electrical circuit other than using a voltmeter? The reason I'm raising this question is because Voltmeters are developed purely using Ohm's Law and so certainly Ohm might have had his own way of measuring the p.d. for...
  27. C

    Measuring the Diameters of the Moon at Perigee and Apogee

    Homework Statement the image below shows the Moonat perigee and apogee. Measure the diameters for the two, and determine the ratio between perigee and apogee idstance.Based on your result, what is the eccentricity of the Moon'orbit? Compare your value with the Moon' s mean orbital...
  28. K

    Vernier Calliper: Measuring Teeth Explained

    Hi all, I have a very quick question. On a vernier calliper, what are the names of the measuring teeth that define the limits of measurement? Thanks
  29. A

    Exploring the Formation of Rainbows - Measuring Refractive Index

    Homework Statement The diagrams below illustrate the formation of a rainbow. Figure 1 shows the general arrangement and Figure 2 shows the path of a ray through a raindrop with the centre of the raindrop is labelled O. Figure 1: Figure 2: a.) Where the ray enters the raindrop in...
  30. O

    Calculating Probability of Measuring +h/2 in 1D HO

    Hello everyone. I have a question that i think belongs here or in the linear algebra section; but now i put it here, maybe someone will move the post if it's in the wrong place. The question: I have a normalized (1D) state in the x-axis in the harmonic oscillator...
  31. S

    Uncertainty Principle & Measuring Momentum: Is There a Confusion?

    we have the relation p= E*C then why do we say that we cannot measure momentum accurately? if we know E then we can find p, and then we can find position at ease,whats more difficult here? are we confusing with uncertainty principle? or is Uncertainty principle confusing us? Or am i missing...
  32. C

    Schools Measuring Science and Engineering Programs at Universities

    How can I tell whether or not a school's degree program is worth it or not? I know to stay away from the online degree mills and make sure that all schools are accredited by recogonized associations; however, I do not know how to judge a school's education benefit. Is there any way to find this...
  33. B

    How to Find Probabilities in Quantum Mechanics?

    Hi, I have a quick homework problem because I am confused. So a wave function with l = 1 in the state: |\psi> = \frac{1}{\sqrt{14}} \[ \left( \begin{array}{ccc} 1 \\ 2 \\ 3i \end{array} \right)\] and i have to find the probability to be in state \hbar, -\hbar, 0 in L_z , so i...
  34. W

    Measuring Computer Speed in FLOPS: Benchmark Software

    Is there a benchmark software available that measures your computers speed in FLOPS?
  35. A

    C/C++ Measuring Time Elapsed in C++ for Accurate Time Tracking

    I am writing a program and I need to measure the time it takes for a particular function to execute. Here is the code I am using to get familiar with time.h #include <stdio.h> #include <time.h> #include <iostream> using namespace std; double diffclock(clock_t clock1,clock_t clock2)...
  36. J

    How Do Astrophysicists Measure Solar Mass Loss?

    From nuclear theory and texts its known that every second 570 millions tons of hydrogen are converted to 566 millton hellium,hence Sun loss 4 mill tons of mass in a second. But ¿how do astrophicisist probe experimentally this number?,have they measured solar gravity field or Earth atraction...
  37. F

    Measuring the temperature of quasars

    Can anyone tell me whether it's possible to measure the temperatures of Quasers from phenomenon such as redshift etc?? As quasers travel with speed comparable to that of light,so does the concept of relativistic temperature come into effect? Are there any research papers available on this?
  38. B

    Advantage of measuring stellar parallaxes from Mars rather than Earth?

    Is there advantage of measuring stellar parallaxes from Mars rather than from Earth? Would it be more accurate than from Earth? Thanks
  39. L

    Measuring Reaction Time with a Simple Device

    Homework Statement The figure below shows a simple device for measuring your reaction time. It consists of a cardboard strip marked with a scale and two large dots. A friend holds the strip vertically, with thumb and forefinger at the dot on the right in the figure below. You then position...
  40. I

    Measuring Distance: How Far Are Stars?

    Hello, This may be a dumb question, but I by no means have any background in Astronomy, I'm pretty much regulated to Science Channel, History Channel, etc. I wish I could dive into all the fields on these forums but unfortunately I was not blessed with the gifts of understanding mathematics...
  41. K

    Understanding Neutrino Spin: Exploring Measurement Possibilities Beyond Decay

    If a neutrino is unaffected by EM and strong forces, and only interacts weakly, how is it possible to measure its spin? I don't mean measurement in a practical sense, as in looking at pion decay.. but how it could be measured in principle. I guess what I mean is are there any physical phenomena...
  42. P

    Measuring Variable Plane Flow Rate

    guys, how to measure the volumetric flow rate pass thru a plane that varies in area (small variation)
  43. J

    Understanding the Equation for Measuring Strain on a Cantilever Beam

    I have a lab where we used the following equation to theroretically measure the strain on a cantilever beam heald stationary at the left end. Measuring back from the right side its length is L2 and the length from the free (right) end to the point where the strain gagues were was L1 (fixed...
  44. S

    Measuring Mass of a Hanging Weight: Stephen's Question

    We did a lab where we had to measure the mass of a weight that was hanging from an air track which pulled the glider through two timegates positioned above the air track. I have to find the force of the hanging weight. F=mg my first mass was .27004kg and the gravity is obviouly 9.8m/s/s...
  45. V

    Measuring Temperature Using a Carbon Resistor

    A carbon resistor is to be used as a thermometer. On a winter day when the temperature is 4.00(Degree C.), the resistance of the carbon resistor is 218.0(Greek "w') . What is the temperature on a spring day when the resistance is 215.8(Greek "W")? Take the temperature coefficient of resistivity...
  46. wolram

    Measuring Red Shift to Confirm Hubble Flow

    Over a period of several years could the red shift of some ideal body be used to confirm the Hubble flow?
  47. G

    Following Schwartz's argument re: measuring (g-2)

    I've been reading Melvin Schwartz's mostly excellent book, Principles of Electrodynamics. He has a section on measuring (g-2) for the muon, and I'm trying to follow the argument. I've attached the figure for reference. He takes the approach of considering an instantaneously comoving frame...
  48. P

    Measuring pH probe potential and interfacing probe with uC

    I am building an automatic acid-base titrator for my senior project. I am using a Freescale s12ub microcontroller. For this project, I will need to interface a pH probe with the CMOS input on a microcontroller. The potential across the probe is supposedly proportional to pH. (-0.06 volt/pH...
  49. T

    Measuring acceleration of gravity

    [SOLVED] Measuring acceleration of gravity Homework Statement The acceleration of gravity can be measured by projecting a body upward and measuring the time that it takes to pass two given points in both directions. Show that if the time the body takes to pass the horizontal line A in...
  50. J

    How can I measure electric field strength for my coursework extension?

    I need to do an extension to a piece of coursework so i thought that a good one (which relates to my initial experiment which was millikans oil drop) would be to try and prove simply that E = V/d. I have about an hour to do it in...does anyone have any ideas how i can go about this? I can get...
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