Tube Definition and 829 Threads

I know hollow tubes have bigger moments of inertia than solid cylinders, assuming their masses are the same. But which one would swing better if you used it like a sword? I'm thinking that the tube would be harder to get moving but would have more rotational momentum and thus be harder to...

Homework Statement I have a copper tube with outer radius r2 and inner radius of r1. Half the tube is exposed to the surrounding air while the other half is embedded into the ground. The outside air temperature is T2 and the ground temperature is T3. What is the air temperature inside the tube...

Hi. I found this strange device in an old physics collection of a Swiss school. What could it be? I think the tag reads "2037. Dolomiti". The Dolomites are a mountain range in Italy. A Geiger counter didn't detect any unusual activity.

Homework Statement A 20 cm long capillary tube is dipled in water.The water rises up to 8cm .if the entire arrangement is put in a freely falling elevator ,the length of the water column is A)10cm B)8cm C)20cm D)4cm Homework Equations Its a theoretical sum The Attempt at a Solution...

I have a project for my physics class that revolves around the idea of building a working pneumatic tube system. I understand how I would build it and such but my teacher wants me to explain the theory behind it. Does anyone have any ideas about the physics behind this or the principles, rules...

Homework Statement The accelerating voltage in a cathode ray tube is ##1000 V##, the electron current density is ##150 \mu A##. a) How many electrons arrive at the screen in a second? b) What's the magnitude of the force exerted on the screen by the electrons if they stop on collision? (Sorry...

I would like to disconnect the secondary windings from a stereo preamp to test the voltages of the secondary windings. The transformer has a 330 - 0 - 330 volt center tapped secondary and a 10.9 volt secondary. It is to be used with house current - 110 or so in Virginia. I have measured the...

Hi there, Hopefully this is a very easy question and you all can just confirm this for me. When calculating heat transfer into a fluid from a heated tube, is it correct to say that the heat transfer coefficient is *not* dependent on the tube diameter? So, if we solve for T_{out}, we get...

Original thread: https://www.physicsforums.com/threads/remove-an-aluminum-tube.952459/ NaHCO3, i.e. sodium hydrogen carbonate, compared to neutrality, is a weakly alkalinic salt, which, although it can, in the presence of a stronger base, such as sodium hydroxide, act as an acid, by surrendering...

Any ideas on how I would remove an Aluminum drop tube from a gasoline or diesel tank? The tube goes thru a 4" steel pipe that extends 3' to 4' above the tank. The problem is that after years of being in the tank the aluminum has seized to the steel pipe. I am thinking about trying to melt the...

Hey guys/gals so here is my problem, I am trying to be able to passively measure the mechanical vertical deflection of fluid passing through an elastic tube approx 1cm in diameter with 0.5mm thick wall that is embedded into the surface of a gelatin mold. Pressure of the flow through the tube...

How much is a circular pipe with holes in its walls weaker than a pipe without holes, specifically when subject to bending and torsional forces? Say I have a hardened steel pipe of some diameter, length and width, and a hole (of max 1/5 the pipe diameter) is drilled horizontally, through both...

in this link here you can see the hot exhaust temperature and cold exhaust temperature at different ratio (hot to cold) with input air/gas at different pressure level. I want to discuss the top here i.e. the data where the input air/gas is at 20 PSIG pressure. You can see that with a 80:20 ratio...

Dear all, I would like to simulate X-ray tube and check the dose rate in the room. My problem is when I simulate 80kV electrons bombard to the tungsten target, there is just a few photons coming out from the tube window. And the dose rate at 1m from the tube is nearly zero which is impossible...

I have a thin tube (4 mm diameter) sticking out of a small box (a bit larger than a matchbox). I want to use this tube to measure the dynamic pressure. How long must the tube be for the results to be reasonably accurate? Intuition tells me the working end of the tube should be kept in the...

When designing the structure of an elevated water tube ride (water flows by gravity through a tube large enough to accommodate 2 people on a float, say 500 lb. max. and the volume of water is constant) how much effect does the object floating on the water have?

I hope many here know about vortex tube and its application. I myself have done some study but were unable to find one answer. If we know the speed of the inlet fluid, then how can the angular velocity of the fluid during its rotational motion can be determined.

Homework Statement If the electrons hit the tungsten target with an energy of 75 keV, find the potential difference. Homework EquationsThe Attempt at a Solution I tried this: (W=eV) V=W/Q V=eV/Q V=75,000/1.6*10-19 V= 4.6*1023 V, This seems wrong because all examples in my...

Why is a GM counter not useful for determining the absorbed energy in a gas?

Homework Statement Homework EquationsThe Attempt at a Solution To calculate magnetic field at 1 and 3 current flowing through sections A and C can be assumed as if current is flowing in a long straight wire along the dotted line . Now since the current and distances are same for 1 and 3 , B1...

Hey, I am from Turkiye, 17 yo and studying at high school. I have a project and would be better to know whether or not my project will work. I tried to draw it simply on paint and will tell you about some important points of it. Image 1 is the main body, its something solid and waterproof. It...

Why cathode rays which consist of electron that do not have any colour are seen as a colourful ray of light in a discharge tube??

For physical experiment I have a project in which I have to measure the speed of sound in the air. 1. If I take an iron tube (inside is air) and a speaker, 2. put the speaker at the beginning of a tube, 3. speaker is connected to frequency generator (with which I can change frequencies)...

Homework Statement The correct answer according to answer sheet is answer B. Homework Equations λn= 2L/n (both ends open) λn = 4L/n (one end open one end closed) c=λf Speed of sound does not change. as it is still in air... (correct assumption? ) The Attempt at a Solution f1= 500Hz L =...

In my lab we are working with a Coaxial coil and stainless steel tube, and are aiming to find the mutual Inductance. I've done some looking around and have easily found the Inductance of a Coaxial cable, and for that of Coaxial coils, but am having trouble with a combination of the two. The...

A recent post here made me think about this so I wanted to ask. Now a x ray tube working principle is basically the opposite of the photoelectric effect, here instead of photons electrons strike a metal target to deposit their energy which is released as heat (IR radiation) and photons. So the...

Homework Statement The open legs 1 and 2 of an U-shaped tube have a diameter of 2 cm^2. In leg 2, mercury is poured. When the distance is 16cm from the mercury level up to the valve K1 , then the valve gets closed. The barometer reading is 76cm Hg. a) How big is the pressure of the sealed air...

Hello everyone, while reading about the X ray tube, I came across this: https://radiopaedia.org/articles/kilovoltage-peak In the second paragraph, it is stated that: "The radiation dose to the patient is directly proportional to the square of kV." I understand that by accelerating the...

Hello. If you blow across an open-open tube, according to the khan academy video, the molecules at both ends contract towards the middle, and then go back outward towards the edges, and the middle molecules don't move. Why? If you are blowing over let's say the top of the left open side, why...

Technically speaking, the problem that I'm working on involves taking the complement of a tube around a knot (an embedding of a circle into ##R^3##) and calculating the homology group of this space. The approach that I'm using is to use a mayer-vietrois sequence. So let ##K## be a knot and let...

Hello. I was studying magnetism with the 9th edition of the Serway book and I think that I've found a mistake. In the cathode ray tube example (one of the uploaded pictures) it is said that the force acting on a electron goes downward, but using both right hand rules that they provide in the...

I have a 5/8" tube that air is blown through. I want to subdivide the center section using .1" tubes so that the same volume of air can be blown through it. It will start as 5/8", but immediately be divided into the separate .1" tubes, then end as a single 5/8" tube. How many .1" tubes would I...

Homework Statement Prove that the hydrostatic pressure difference between the liquid surface and the base of rightmost tube is ρgh (h is the vertical distance of the liquid surface from the base ) ? Homework EquationsThe Attempt at a Solution I would like to prove this result just out of...

Homework Statement A glass tube is bent into a U shape. Water is poured into the tube until it sands 12 cm high on each side. Kerosene (density = 870 kg/m3) is added slowly to one side until water on the other side raises 5 cm. What is the length of kerosene column? Homework Equations (ρhg)1 =...

Hi I don't know if anyone here design tube power amps. I am calculating the gain of the class AB output stage of push pull tubes and output transformer. Class AB by definition has a small signal region that both tubes are working and is operating in pure class A. Only when input signal is large...

I am making a physics simulator and this problem is tricky. You have two freely moving objects with known masses and velocities in a frictionless environment. The first object is a ball and the second is a pipe. They are moving toward each other. I need to know what formulas are used to simulate...

Just has my first CT scan ever for low dose cardiac scoring. Held my breath twice with gantry in fixed position and then once again with gantry spinning. I thought I would have heard the high pitched x-ray when beam energized but didn't at all. All I heard was normal fans and the mechanicals of...

What causes there to be a node at a closed end of an air column and an antinode at the open end of a air column? Why doesn't it change as the wave oscillates?

Hello For the purpose of the experiment, I wonder what the maximum dimensions can have a transparent tube, I thought over a diameter of 30cm and a length of 1-1,5m and from what material should such a pipe be made. I would like to get a high vacuum (about 0,2-2Pa)

I am reading about gas discharge tubes and can't work out the types of energy and energy conversion that occurs in a gas discharge tube. Initially before the tube is switched on you have an inert gas with kinetic energy. As soon as the tube is switched on there is an an electric field between...

Let us start with a bit of background information. I am working on seeing if I can construct a very small version of Keith Lofstrom's Launch Loop concept, to see how well I can get it to work. To do this, I am using a larger clear plastic tube as the sheath, and a smaller plastic tube with...

Is it possible to get a laser tube with the ends unmirrored, designed such that a photon being sent through will have a good chance of stimulating another photon to be emitted? If this is possible, then a beam of light going into the tube would be roughly doubled in intensity. When stimulated...

Imagine that I have a straight, statically-charged, cylinder-shaped tube with arbitrary (ideally infinite) extent. The charge is distributed evenly over the tube such that the field inside the tube is zero. For convenience, let's line up the tube centered along the x-axis such that the...

Thought I would share my latest project. I decided to make a stereo amplifier out of Vacuum tubes. I think I finally have the noise and distortion levels as low as I can get them. The amplifier outputs about 88W rms per channel before it clips the output. Here is the internal wiring This is a...

Given a tube that requires a series of holes to be drilled into it, in general terms, what would be the optimal pattern/shape/spacing of holes to maintain structural integrity, particularly against a force acting in an axial direction ie, on the end of the tube? That is, to prevent buckling?

How does the capillary tube decrease the pressure on the liquid when its diameter is smaller? How small diameter of capillary tube is helpful in causing more pressure drop? And how, when pressure drops, the liquid instantly cools down?

Homework Statement 'A shell and tube exchanger is used to do heating, with single shell and 2 tube passes. There are 70 tubes each with an outside diameter of 25mm and length of each tube pass is 6m. ' I am wondering whether the 70 tubes are in between the 2 tube passes, or is it 1 tube pass...

I have a tube light at my home which produces this sound: The sound can be heard for a long time every time the light is switched on, but it stops after about half an hour of switching on the light. What is the cause of this sound?

Homework Statement A long tube that is open at both ends is used to construct a musical instrument. The sound waves that enter the tube are generated by a taut wire with a tension of 600 N and a linear mass density of 0.031 kg/m. If the length of the tube is 2.4 m and a hole is cut in the side...

Hi all, my question is if i have a length of carbon fibre tube, one is round the other is oval and orientated along its longest side is it more stiff than the round one? Reason for asking is i am trying to make a telescopic carbon fibre pole that is more rigid than the round ones on the market...