What is Meter: Definition and 309 Discussions

The metre (Commonwealth spelling) or meter (American spelling; see spelling differences) (from the French unit mètre, from the Greek noun μέτρον, "measure", and cognate with Sanskrit mita, meaning "measured") is the base unit of length in the International System of Units (SI). The SI unit symbol is m.
The metre is currently defined as the length of the path travelled by light in a vacuum in 1/299 792 458 of a second.
The metre was originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole along a great circle, so the Earth's circumference is approximately 40000 km. In 1799, the metre was redefined in terms of a prototype metre bar (the actual bar used was changed in 1889). In 1960, the metre was redefined in terms of a certain number of wavelengths of a certain emission line of krypton-86. The current definition was adopted in 1983 and modified slightly in 2002 to clarify that the metre is a measure of proper length.

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  1. F

    Mathematica Mathematically meaningful meter

    The "size" of the SI meter has its basis in the metric system and it was officially accepted in 1799. We know its size doesn't match its intended 1/10,000,000th division from the equator to the pole, thus it is somewhat arbitrary. Even though the SI meter is defined differently its "size" is...
  2. T

    Sprinter Speed at Finish Line in 100 Meter Dash

    A sprinter can accelerate with constant acceleration for 4.0s before reaching top speed. He can run the 100-meter dash in 10s. What is his speed as he crosses the finish line? I need help with this problem. I know that for the last 6 seconds because he has reached top speed that he has...
  3. V

    What is the significance of inverse meters in astronomy calculations?

    Hi, I'm doing some astronomy work and one problem involves using Rydberg's constant. However, it is inverse meters and I'm confused. Does that mean that it is 1/109737361.6 m? Thanks.
  4. T

    Can someone check my precision for a meter stick, vernier cailper, and micro

    [SOLVED] Can someone check my precision for a meter stick, vernier cailper, and micro Meterstick Precision: 1 mm Example: 607 mm Vernier Caliper Precision: .1 mm Example: 41.5 mm Micrometer Precision : .01 mm Example: .05 mm what I'm asking basically is, is the precision I...
  5. K

    Measuring dB Level: Receiver or Field Strength Meter?

    can anyone describe wat is dB level. can dB level be showed through receiver or field strength meter? thx for helping
  6. K

    Field strength/intensity meter and receiver

    [b]1. Homework Statement [ i was asked to measure the signal strength. so in my set up for the experiment, is the field strength meter needed together with the receiver. how am i going to set these together at the antenna.izzit , connect the receiver to the battery, antenna to the receiver, AND...
  7. J

    Can Dedicated Digital Volt Meter ICs Enhance Microcontroller-Based Projects?

    Hello All, I am working on a microcontroller-based control circuit that can generate different frequencies for experiments I am working on, but I also want to add a feature that allows the microcontroller to take voltage measurements from my test setups. The 68HC12 controller board I am using...
  8. M

    Question about vacuum and vacuum meter

    I wonder why vacuum is sometimes measured in range from 0 to -1 bar. Is it because of it's measured relatively to normal atmospheric pressure? I guess that normally, vacuum shoud be in range of 0 to 1 bar or something? Can you help me understaning what terms "underpressure" and "overpressure"...
  9. C

    Is the Smart Tweezers R-L-C Meter Accurate Enough for Through-Hole Devices?

    Recently, I found a R-L-C Meter called Smart Tweezers R-L-C Meter from the website of http://www.advancedevices.com/products_tw.htm" . It is quite similar to the Chinese Chopsticks that can be used to take measurements from the devices already mounted on a board. For the through-hole...
  10. H

    Finding the Mass of a Meter Stick Using Torque Equations

    Homework Statement A metre stick is found to balance at the 49.5cm mark when placed on a fulcrum. When a 47.7 gram mass is attached at the 1.5cm mark, the fulcrum must be moved to the 38.6cm mark for balance. What is the mass (in grams) of the metre stick. Homework Equations Torque =...
  11. G

    Uncertainty/errors in meter stick measurements

    Hi just got a couple of question about errors in measurements. I have a table of results of different meter stick measurements which are accurate to 0.1 cm. Now a meter stick reads to 0.1 cm and the uncertainty is usually 20% of the smallest reading. so all of my readings should be +/-...
  12. F

    Which direction did they measure a meter?

    Okay, a meter is the distance traveled by light in 1/299792458th of a second. It's relative, so the actual measure of a meter changes depending on your velocity (I won't even go into "Relative to what?", though I do sort of wonder if one could find a 0 point of velocity by measuring light going...
  13. D

    Lux Lumens and Watts per square meter

    Homework Statement I am looking for a conversion factor that will ultimately get me from units of lux (illumination) which is a weighted scale of light intensity, to watts per square meter, which is not weighted. Homework Equations None availiable The Attempt at a Solution I am...
  14. A

    Designing a Multirange Ohm Meter with a D'Arsonval Movement

    Can someone help me to design the multirange ohm meter using permenant magnetic moving coil movement...
  15. G

    Calculating Detection Distance of Superconducting Gravity Meter

    Homework Statement A superconducting gravity meter can measure changes in gravity of the order = 1×10-11 (delta g)/g. You are hiding behind a tree holding the meter, and your 78 kg friend approaches the tree from the other side. How close to you can your friend get before the meter detects a...
  16. A

    What is the resistance of meter coils?

    Hi, Just had a bit of a heated discussion with a friend of mine about electricity meters and I decided to get some info from you chaps so I can promptly add some ammo to my argument next time we meet! The claim is that you will get a low resistance reading between phase and neutral meter...
  17. E

    Giant VU Meter Project | University of Kentucky

    Hello all, I'm a freshman electrical engineering student at the University of Kentucky. I'm also a DJ at http://wrfl881.org" . I was browsing around the awe-inspiring http://www.blinkenlights.de/" at MIT. Now on our campus we have a convienently tall building atop which sits our...
  18. F

    What Is the Tension in the Remaining String After Cutting One Support?

    Hi, this question was from an archived thread but I have another relevant question that was not answered by any of the posters-- P.S. The answer to c is NOT mg. Homework Statement A meter stick (L = 1 m) with mass M = 0.409 kg is supported by two strings, one at the 0 cm mark and the...
  19. R

    Can You Build a Flow Meter with Basic Electronic Components?

    how do i make a flow meter, using whatever like resistors, capacitors, and make the flow meter go like 10 second per etc help need...i am in EE 2ll basic circuit engineerin? thanks
  20. B

    Physical pendulum and meter stick

    A physical pendulum consists of a meter stick that is pivoted at a small hole drilled through the stick a distance x from the 50. cm mark. The period of oscillation is observed to be 1.656 s. Find the distance x. I know I have to find the moment of Inertia and I believe the equation for this...
  21. M

    How To Determine Newton Meter Force

    Hello! How do you calculate or determine Newton meter force requirement and rpm's for an electrical motor in the following example: A device that utilizes a shaft that is 2 inches in diameter and 6 feet length. It needs to be able to lift 10 pounds and distance of 7 feet in 6 seconds. I...
  22. F

    How can I convert kilograms to centimeters?

    ^^^^^^^^^^^^ i forgot :P
  23. B

    Prepaid Electricity: A Modern Approach to Managing Energy Usage and Billing

    hi there! i don't have this project, i just want to know if anyone can help me. I am a graduating student and i would like to proposed prepeid electricity meter as our thesis proposal. can somebody help me? or give me other ideas as a thesis proposal.. thanks a lot and god bless... :smile:
  24. N

    Understanding Analog Meters: How to Read and Interpret Measurements

    Sorry, this sounds like a silly but I grew up in the age of auto-ranging multimeters. Say you have a scale, 1 to 10 and you select your scale as 1 miliamp. I presume if the needle is at 7 then that means 7 miliamps and NOT (7/10) 0.7 miliamps?
  25. F

    Masses hanging on massless meter stick problem

    Two masses (mA = 3 kg, mB = 6 kg) are attached to a (massless) meter stick, at the 0 and 75 cm marks, respectively. a. Now, if mass B was removed, how much force would need to be exerted at the 100 cm mark in order to keep the meter stick level? b. Now, if mass B was removed, and no...
  26. F

    Unusual Readings from Frequency Meter in Quantum Mechanics Lab?

    In quantum mechanics lab our frequency meter shows ~50 Hz when it is plugged into a device which is not turned on. Is this a problem or an effect that I don't know? :rolleyes:
  27. A

    Building a Gravity-Powered Vehicle: 5 Meter Challenge

    i have to build a vehicle "powered soely by gravitational potential energy that will travel at least a linewar distance of 5 meters under its own power. no elastic potential energy (such as a mousetrap) allowed" i was wondering if anyone out there had any idea on where to start or knew of a...
  28. N

    If power were applied to a one meter cube of quartz crystal

    Is it true that, if power were applied to a one meter cube of quartz crystal and the crystal were driven to the breaking point, the gravity waves produced would definetly, 100%, be orders of magnitude too weak to be detected? Apparently Albert Einstein calculated that
  29. electronic engineer

    Do I need to supply a 555 IC with 5V for a temperature intensity meter circuit?

    I've attached a circuit schematic for the temperaure intensity meter... R1 is the PTC the first 555 works as monostable so it triggers second 555 to produce Astable pulses with given frequency depending on the values(R3 and R3 and C4) anyway i want to ask if i have to supply my second...
  30. A

    Calculating Speed of Falling Meter Stick

    First let me say I appreciate everyone on these forums who takes the time out to help. My question is as follows: It has 2 parts. Part 1: A uniform meter stick (1 m long) is held on its edge against a frictionless table. The meter stick is released and it falls to the table. Part 2...
  31. T

    What would an Ideal Volt Meter measure if

    1 of 2: What would an Ideal Volt Meter read if an Ideal Capacitor had a charge difference of... 6.25 quintillion electrons (6.25 X 10 to the 18th) between its two plates? In other words... if there were 6.25 x 10^18th extra electrons on one plate... and you connected an Ideal Volt Meter...
  32. electronic engineer

    Light Intensity Meter: Schematic, ICL7107, Eagle & More

    This is the schematic of my project (figure7)...but I don't know how to add display (ICL7107) using eagle, and how to power display .. how to connect the output voltage of stage2(second opamp) to the display? http://www.seas.upenn.edu/~ee205/Labs97S/Lab7/Lab7.html anyway , take a look at...
  33. J

    Find Tension of Meter Stick Attached to Wall

    The problem states: a 0.13-kg meter stick is held perpendicular to a wall by a 2.5-m string going from the wall to the far end of the stick. (a) find the tension in the string; (b) if a shorter string is used, will its tension be greater than, less than, or the same as that found in part (a)...
  34. P

    Special relativity help: meter stick moving at 0.60c

    A meter sticks moves with velocity 0.60c relative to an observer. The observer measures the length of the meter stick to be L. The problem states that 0.80<L<1.0 m must always be true. So far, I have determined that Gamma = 1/sqrt(1-0.60c^2/c^2) = 0.8. What I don't understand is why there...
  35. A

    Solve the Balance: Meter Stick Mass Calculation

    "A meter stick is found to balance at the 49.7cm mark when placed on a fulcrum. When a 50 gram mass is attached at the 10cm mark, the fulcrum must be moved to the 39.2 cm mark for balance. What is the mass of the meter stick?" thats the question and the last one on my homework and its given...
  36. C

    Design a Container to Survive a 15 Meter Drop

    Hey, I know there are already many of this threads, but I checked them all out and none can help me in my project. Well, in my project I have limited amount of materials, and I have already tried out various designs with no success, so any help would be great. Here are the details: Drop...
  37. P

    Ph meter or acid/base titration?

    Which would you use advising, a ph meter or acid/base titration? advantages/disadvantages to both?
  38. wolram

    Corrosion on the cable fooled my test meter

    Yes i had two today, one was because corrosion on the cable fooled my test meter, the other was because a door swich knob was not in mechanical contact with the switch, two in one day is just not fair, i must be getting sloppy, as i have only had two others in my life ,but then i must...
  39. S

    How to Calculate Volume Flow Rate Using a Venturi Meter

    these are the following data: diameter(pipe)=0.1m diameter(throat)=0.05m difference in pressure=55kpa Cd=0.98 question requires me to find the volume flow rate. 1)i know i need to find h(diff in pressure/density*gravity) i have a doubt here where can i just leave the pressure in kpa...
  40. B

    If the tides on earth one meter high how far away is the moon?

    Hi all, I am reviewing for my final and cannot seem to find how to solve the following If the tides on Earth one meter high how far away is the moon? What equations should I use to calulate how the moon effects the tides on earth?
  41. M

    Understanding the Circuit Diagram for an Amp Hour Meter for Beginners

    This thread is a continuation of my previous thread, except this one is primarily focusing on the contruction of an amp hour meter and programming it, rather than the gathering of parts for it. (since the parts have just arrived, very slow mail order) I am getting very confused when looking...
  42. A

    How Long Does a Meter Stick Appear When Traveling at Light Speed?

    I know the formula to use for this problem, but cannot seem to make it come out with a reasonable answer. Can anyone help? If a meter stick travels at the speed of light relative to an observer, how long does the meter stick appear to the observer? (I cannot seem to make the radical...
  43. M

    Find the mass of the meter stick

    A uniform meter stick of mass M has a half-filled can of fruit juice of mass m attached to one end. The meter stick and the can balance at a point 12.5 cm from the end of the stick where the can is attached. When the balanced stick-can system is suspended from a scale, the reading on the scale...
  44. H

    Can one read a meter stick down to a tenth of a millimeter?

    Can one read a meter stick down to a tenth of a millimeter? For example, could I reasonably measure an object as 32.43 cm using a meter stick?
  45. M

    Solving Amp Hour Meter Problems: Wiring Series vs Parallel

    Hello, the other day I got an hour meter to help me keep track of the amp hours I have put into my circuit, but I am not too sure how to hook it up. it came with a page of instructions giving a few diagrams on how to connect it, the only 2 that made sense for my application of it was to either...
  46. J

    Equilibrium meter stick problem

    Alright well I have an equilibrium problem to do and I have sat here and stared at it but it does not really seem to make sense or I can't see a way of solving it: The problem is this(also see attached image): One end of a uniform meter stick is placed against a vertical wall. The other end is...
  47. K

    Watts per Square Meter: Learn the Basics

    Watts per squ meter?
  48. F

    Water flow venturi meter problem Heeeelp please

    water flow venturi meter problem! Heeeelp please :) Hi, The objects of my experiment where 1) to find out the theoretical and experimental pressures in a venturi tube, 2) To determin the coefficient of discharge for the venturi here is the data i collectec...
  49. M

    Measuring Liquid pH: Is a Soil Meter Accurate?

    Does anyone know if it is possible use a soil pH meter to measure the pH of liquids (ie. not soil)? Or a better way to phrase it, is there any diference between a soil pH meter and a normal pH meter meant to be used on liquids that would cause inacuracies or other problems if one was...
  50. marcus

    Photons in 1 cubic meter at temp T

    Benzun started a thread with this question: I have replied to that question, and want to extend the question (without diverting Benzun's original thead). the related question is, if you have a hollow box or cavity at some temperature T, then how many photons per cubic meter are in it...
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