Measuring Definition and 962 Threads

how do i measure temperature of a current carrying conductor? i need to know the increase in temperature as i heat it up by passing a current through it. i read somewhere that i could use heat transfer convection equations to find it, but then i would need the precise value of the heat transfer...

I'm having problems with our pressure measurements on a pretty basic PVC water flow system. I drew up the general design in paint and attached it so you can have a visual of what I'm talking about. The second attachment is a picture of the actual pipe design. We're controlling the flow rate...

An object floats if it is less dense than water. I'm assuming that an aircraft carrier can float because there are several rooms in it with air. What happens when the door on the upper most floor is opened? Does the air inside that room still contribute to the total average density of the...

Hello, I want to measure color of some objects underwater. I believe that one way of do that would be using the RGB system on photos. The other way would be measuring absorbance directly with an spectrometer, but I don't know how I can standardize my conditions. I have to measure the color of...

I need your help in understanding the concept. Actually, I am trying to understand the grounding concept here: Attached is the snapshot: Hi Folks, I need your help in understanding the concept of how to measure the output voltage. 1. Initially, I tried to monitor the voltage...

I completed high school 9 years ago... please bare with me :) My problem is with how they calculate the actual answer - this is from an example problem in my textbook. Homework Statement A calorimeter cup is made from 0.15kg of Alu and contains 0.20 kg of water. Initially the water and...

In my physics class for an assessment we designed our own lab. In our lab we had plastic cups and cut small holes in the bottom ranging from 0.3 cm to 1.3 cm diameters. We then measured the amount of time it took for different volumes of water, detergent, syrup and rubbing alcohol. I...

Need help calculating friction and normal force for "Measuring Friction" Lab Hey guys, I'm not great at physics and have a lot of work ahead of me so I could use some help. The lab setup is a wooden block sliding on a wooden surface. There is a weight attached to the block by a string that's...

Homework Statement A resistor (R) and a capacitor are connected in series to an AC supply. You are measuring the voltage across the capacitor with an oscilloscope. however, the oscilloscope is not ideal. you may model the oscilloscope as an ideal voltmeter in parallel with an internal...

Hi. I'm wondering if it's an acceptable method of measuring distance between two objects of known size by averaging their scales. In my case I have a photo of birds on the water. Each bird is known to be about 37cm long. I want to find the distance between two of them on the photo, the nearest...

On my senior project, I've figured out everything I need to measure all the parameters I needed EXCEPT force. I know that I need to use strain gauges, and I've used them in my instruments class with Labview and a DAQ. While I'm still using Labview, I'm now using an Arduino so things are a little...

Which experiment does show that electron has a spin of magnitude of \frac{1}{2}\hbar? I guess, Stern–Gerlach experiment shows that electron has a kind of intrinsic spin; because of which, particle beam gets deflected in some specific way under the application of an external magnetic field...

Homework Statement I have a university project that involves comparing various paints with regards to how they affect the insulating properties of houses. As part of that I would like to measure the emissivity of the paint for a variety of wavelengths. Unfortunately I can not simply heat...

How is the age of the universe measured? Is it by the distance light has traveled since the big bang? Does that imply a closed universe?

Hi, I have a lawn mower engine and I need to read and adjust its rpm precisely. I am totally lost. I would like to ask how some of you would approach this problem. What I have right now is I am going to buy an Arduino circuit board controller. Then I am going to attach a tachometer onto...

Hi all, I want to measure the white noise produced by a resistor in my circuit. In order to do this I did the following: 1. Ground the excitation voltage of the circuit and measure the white noise voltage produced by connecting the output of the circuit to a 8.5DVM 2. Subtract the Avg DC...

Hi. In order to measure the I-V curve of a normal diode in pulsed mode, I set up the following experimental kit. The experimental results do not change with pulsewidth, which is quite long (us regime), and low frequency (200hz and less). An HP pulse generator is connected via BNC cable to an...

I am wondering how space geographers would measure curvature of space around a large isolated star. i am thinking of the set up where there are two nearby spheres surrounding the star whose circumferences are already known. The remaining step is to measure the length of a radial geodesic segment...

I am working on a problem where I am heating a hollow cylinder from the outside with a NiCr wire which is then insulated. The pipe is cooled by running water through the center of the hollow pipe. I would like to find the heat flux transfer rate outward. So my set up from the inside to the...

Homework Statement An isotope of hydrogen passes, without deflection, through a velocity selector that has an electric field of 2.40 × 10^5 N/C and a magnetic field of 0.400 T. It then enters a mass spectrometer that has an applied magnetic field of 0.494 T and consequently describes a...

I tried 5 times to get this problem, so I'm sort of heavily invested in it. Homework Statement How fast is the moon moving as it orbits Earth at a distance of 3.84 × 10^5 km?Homework Equations I'm using the kinematic equation: v = Δd/Δt Here distance will be 2∏r (I know that the moon's...

What are the advantages to using one system to measure an angle over another. For example why do we measure angular velocity in radians instead of degrees? Are there any intrinsic advantages to one unit over another? Thanks AL

I have a solenoid that is controlled by a PLC. I want to know what the delay time is from the time the PLC sends the signal to engage the solenoid to the time the solenoid is fully engaged. The time will be very short (milliseconds), but I need to know what the delay time is to within 5ms...

i have done the maths based on an online conversion calculator that said 1 liter of air is equal to 0.001m^3 in volume. my chemistry teacher tells me that my maths is wrong but won't tell me how... here is what i wrote: Failing the above, a larger crucible would hold more oxygen and the...

This has been nagging me in the background of my mind for many years and I've decided to get it sorted. I note that I'm not sure if this should be in the classical or quantum forum. I have heard it mentioned by many and often when referring to the inherent uncertainty when measuring...

Can anyone tell me what will happen to a length og a rod if it is measured in a running train and why?

some device or contraption to measure point impact velocity - ballistic pendulum ? i hope you guys and gals can point me in the right direction for a prototype i am working on. I am looking for a device that measures impact velocity. much like a ballistic pendulum only much sturdier than the...

1). Would you always go through a selection criteria to help decide on the most appropriate one to use if you had no prior knowledge of the system? 2). Would the environmental parameters need to be assessed for any kind of system regardless of the conditions? 3) Would the dimensions of...

Hello, everyone! Any ideas how to measure drag or drag coefficient on a body of simple shape? We should conduct an experiment without use of sophisticated equipment. Thank you!

I have a cheap oscilloscope that is rated for 10V input. I want to measure the quality of the output of my power supply due to a belief the DC filtering circuit isn't working well and producing harmonics in the signal (ripples). The output voltage is at a higher voltage coming out of a...

I'm trying to measure the resistivity of a sample of A356 to back out the thermal conductivity. I do not have anything sensitive enough to measure the micro-ohm resistance (my sample is 0.5" x 0.25" x 3"). If I want to use an oscilloscope or multimeter to measure the voltage drop, I should...

Hello, I have been researching a bit of quantum physics, and I have encountered a conceptual problem. Basically, we have an electron whose spin is aligned along some axis, and we wish to measure the spin along the z-axis. So what we do, is that we put the electron between two magnets. This...

I have been reading and I think I understand what they were doing in CERN (OPERA) when they measured a speed faster than light. But I am not sure so I would like to ask you if I understand this right. As I understand it they "shot" two microwaves. The first one went straight to a "goal" but...

Can anyone describe an experiment that would be used to measure orbital angular momentum?

I have taken the challenge to measure the Earth's gravitational force, g, without knowing the mass of an object. To do this, we took a spring and had it oscillate vertically and determined the period T. Here is my theoretical development: F = -kx x(t) = Acos(ωt+θ) where ω = √(k/m) of...

Hi experts what is line integral - for example if I can draw graph of parabola and i can calculate the area under the graph. But how can i measure the length of parabolic path.

hello, If I had a substance (k) and heated it from Temperature1 to Temperature2, for z seconds, is there any (simple) equation that would give me the temperature (x) of this substance at the end? (knowing, of course, the substance's specific heat(C)) I found that: Q(energy exchanged during...

Hi, First and foremost, I hope this question doesn't sound stupid! I am doing a lab for school in which I have to measure the resistance of a wire. As part of that, I have to measure the p.d across the wire and the current through it. After collecting my results my teacher said that I...

Hi everybody. I am going to exam on Monday. I would like to make a experiment on how to measure the coefficient of friction. I know, that I can find the mu(s), by taking the tan to the angle α. μs = tan(α). Is there somebody, who has some others ideas how to measure that? Somebody...

Hey guys, I am working on my lab with BJT with a Common Emitter Configuration. One of the steps asks me to measure the DC Operating Point, however I am not sure what they want. What I think they want is for us to find the point VCE where the slope of the collector current vs VCE intersects...

I don't have any specific numerical values for this, as it's a general question, but hopefully I explain it well enough using only words: If you plot a graph of position vs. flight time (of a sound pulse, for example), what is the slope of that graph going to be? (That is, what does the slope...

Hello I know this topic must have been done to death already, but i can't seem to find a satisfying answer. As the title suggests, my question is, what experiment proves that the uncertainty principle is not just a result of our flawed measuring techniques? From what i understand, when we...

Expressing the cosmological distances with conventional terms is very confusing. For instance, if we say that "a galaxy is a 1 billion light years away" what this is really mean? 1. If all moves stopped (moves in space and expansion) the light will travel from that galaxy (center of it) and us...

I have a question, but I'm a neophyte so please correct my premise if it is wrong. If it is true that in an expanding universe the space between any 2 points increases than wouldn't it be true that the space between the end points of a measuring rod (e.g. a light year, or more fundamentally a...

Homework Statement "Determine a surface temperature value for the Sun from the angular diameter of the Sun and the solar constant." Homework Equations L=4π(R^2)σT^4 The Attempt at a Solution At this point my only stumbling block is I don't understand the relationship between the solar...

Hey physics forums I was kind of curious if there how people measured electric field and of course guass's law before we had computers, so I talked to one of my professors about it. He told me that a long time ago people used something involving plates and soap bubbles to prove that guass's...

In an experiment that I conducted, I was instructed to measure the mass of a substance (NaCl) in it's container BEFORE measuring the mass of just the container. Is there a logical reason behind doing it in this order rather than measuring the mass of the container FIRST AND THEN measuring...

If I do an experiment where I want to work out how fast a certain amount of water will empty from an ordinary plastic bottle elevated greater than horizontal, what Physics could I apply if I measure the angle at which it is emptied, the height above the ground and how long it took to empty. I...

1. I need to set up a lab. The goal is to find the force of friction between a track and a ball. The track is flexible and tilted so that it slopes down. Looking at it from the side, the track looks like half of a U. The ball is released from the top of the track and somehow I have to figure out...

Hello, As a concrete model to refer to, I'll work with the one-particle system in a potential box with infinite edges. Inside the box is a potential barrier of height V. Let's say we've measured the energy at one moment to be E < V. The probability of measuring the particle inside the barrier...