I have been wondering why train simulators(and trains themself) have a kW specification, AND a maximum force indication.

If I would calculate the speed of a train using some formula, then where is the power value used for?

Does it have something to do?

Or is only the maximum...

What does power have to do with the speed calculations of a Train?]]>

Heat transfer from a closed cylinder filled with fluid]]>

If you condense an atom, would it make a black hole?]]>

Do rare earth magnets interfere with RF?]]>

I do an calorimeter experiment at temperatures around 40 mK. To get more grip on the time constants that are associated with the heat flows, I calculate the thermal resistance as well as the heat capitance of the materials in the set-up.

We assume that Newton's law of cooling is the...

(Specific) Heat capacity of brass at milliKelvin temperatures]]>

There's lots of measurements on transitions between various hydrogen/deuterium energy levels but not (it seems) to the limit where n = infinity.

Alternatively...

Measure ionization energy (Hydrogen/Deuterium)]]>

When reading a bit about substractive color mixing, a question came up.

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I understood that when mixing Cyan, Magenta and Yellow paint, you would get black because all these 3 colors that get reflected by each corresponding paint are absorbed by the other...

Question about subtractive color mixing]]>

A car is traveling down the highway at a constant velocity, is work being done?

He says no because the net force is 0

Now the road is not frictionless . I asked....

Why isn’t work being done]]>

Equations to model tennis ball motion]]>

I assume the Voltage waveform in the wire is 120sin(60t). This circuit only has a 14ohm heater in it, according to Ohm's law I=V/R. The current is equation to I(t)=120sin(60t)/14...

Fields from an AC wire]]>

Basically I have a normal water bottle, 0.5 L (maybe a little more, up to 0.6 L but definitely not more) and I always heat the water bottle up on a radiator...

Heating up a water bottle]]>

I need something that would measure vibrations along an axis, so instead of buying a bunch of accelerometers I thought I’d quickly make smth myself. I’m majoring in engineering and not physics, so while I have no problems with the construction, I’m kind of stuck with the physics aspect.

I...

Damping and ~~pendulums]]>

Can indistinguishable particles obey Boltzmann statistics]]>

Assumptions:

- An engine efficient enough that you can afford to thrust for very long periods - maybe fusion? (OK, that's fiction)

- A lot of maneuvering (eg. you could thrust until turnaround point and then decelerate)

- With a lot of...

Gyroscopes on spaceships]]>

, but if they aren't please say so), how would you find when the spring will oscillate with a rate of change less than X (I'm using this to determine when the...

Find when spring oscillates less than X]]>

I am new here so please don't be too hard on me yet and move this post if i placed it in the wrong forum.

I am developing a little experiment game and i want the train to drive using real physics, but I am really bad at physics.

So my question is is how do I calculate the friction of...

How to calculate Train speed with friction? (developing a little experiment game)]]>

Does anyone know how to measure the color of a Post-It note?]]>

Deriving the ionization energy of a hydrogen atom]]>

Why can’t gas support a solid body?]]>

What is electricity made out of?]]>

I left a one gallon jug of water sitting in the kitchen floor. When I came back maybe 4 or 5 hours later there was a pool of water around the jug. I looked at the jug and found water slowly streaming out of the top. The jug was...

Strange Phenomenon With Water]]>

If two particles are extremely close together, there should be an extremely large force. If we then build a sphere around...

The shell theorem]]>

Could that mean...

Is the time dimension more fundamental?]]>

Photon upconversion and second law of thermodynamics]]>

Diffraction Gratings]]>

On

The Forgotten Anniversary: 100 Years since Emmy Noether's Theorems]]>

Gauss' law for magnetism]]>

I am developing a Train Simulator kind of program where I calculate speed each frame.

I currently do that by:

Speed = (f/m)*elapsed frames*time between frames

This works, but goes wrong when there are framerate drops or if the force changes, thats why i want to calculate the speed with the...

How can I calculate speed based on previous speed?]]>

So what’s everyone favorite topics when it comes to physics ?

My favorite topics are the Big Bang inflation,string theory, and parallel universes theory :)]]>

I'm current studying magnetostatics and I'm struggling to understand the equation for

Calculate magnetic potential of a given current density]]>

I had been reading about shelling in rails: https://patents.google.com/patent/US2853775

Here you can see (as stated):

Residual tensile stresses due to high compressive loading]]>

Noise level at high-rise buildings]]>

1.) What is the distance between electric field lines? Is it just the distance between two points on adjacent electric field lines that...

Electric Field Line Strength]]>

Warm air goes up...reason on a microscopic scale?]]>

Polarity of magnetic field in a conducting wire]]>

$$Re(Ee^{jwt})=\frac{1}{2}(Ee^{jwt}+E^*e^{-jwt})$$

The book doesn't explain what ##E^*## is, it just lists the formula. Re = real, as in take the real part. E is the...

formula unexplained in textbook]]>

Who contributed to Maxwell's Equations and how?]]>

Can ultrasound pass through metal?

How much of it can pass and how thick the metal can be?

I couldn't find anything online, I only found some contradicting and unclear information.]]>

e

e

where r = xi + yj+zk

x = x(u,v,w)

y=y""

z=z""

cant understand why.]]>

I will first show how the method I used works for a simpler case where Magnetic field and current are...

Magnetic force on a current carrying wire]]>

Question about Electrical Energy]]>

Gauss’ law and an infinite rod]]>

What was so extraordinary about Landau damping?]]>

First, what is it? Is white light the result of all color wavelengths present in an area?

Second, if so, then why is there no interference in waves of light (or is there)?

Third, if photons all travel at the same speed, then...

Composition of Light]]>

Say you have two objects with different masses in a vacuum sitting on some kind of plank. Next, you remove the plank from both at the same time. The heavier object has a greater inertia, which means that it has a...

Inertia - two objects falling]]>

,

where

Flux with a non-uniform electric field]]>

Yesterday I sat down, and just for fun, decided to calculate the coefficient of kinetic friction for the all electric Ford Focus. I keep getting the wrong answer, and it is driving me crazy. Here are the facts.

Battery: 23 kWh.

Curb weight: 1,651 kg.

Maximum travel distance before a...

The coefficient of kinetic friction for a Ford Focus]]>

Why were Newton's laws of motion discovered so late?]]>

At which point is gravity the strongest?]]>

The Play of Gravity]]>

I've peformed Galileo's experiment with inclined planes, using a ramp of 88cm (divided in 4 parts of 22cm), inclined by a height on the right-edge of 4cm. I've measured the following,

1/4 of the ramp (22cm): 1.75s (error of 0.1s)

1/2 of the ramp (44cm): 2.70s (error of 0.1s)

3/4...

Galileo's Experiment with an Inclined Plane]]>

"In general, the internal energy will be a function of temperature and volume, so that we can write [tex]U =U(T,V) [/tex]"

How do we know this intuitively and how do we know that internal energy is not a function of pressure as...

Why is internal energy not a function of pressure?]]>

Also what good does this do. Why would I want to know the electric flux of something?]]>

I know that this applied force will have an x and y component; the y component will propel it upwards, but what I am confused about is the x component of the force. I know that...

Force applied to a sphere off center of mass]]>

"We have been discussing the emission spectrum of an atom. A closely related property is the absorption spectrum. This may be measured with apparatus similar to that shown in figure (5-1) except that a...

Only certain emission lines show up in absorption spectrum]]>

Is it because if you put a negative charged object near the soda can the side of the can nearest to...

Movement by electrical induction]]>

I told them it was white gold (which is an alloy of 58.5% gold and the rest is other metals). They said it was fine, but later told me they didn't really know what...

MRI and metal heating]]>

Can gasses be contained with centripetal force?]]>

I read about superionic water in a NY Times article...

SuperIonic Water]]>

electrons in these atoms or we need a more powerful

one?]]>

I think this issue periodically resurfaces in PF. I have found a similar discussion in this closed post and possibly others. I'm posting this because I'd like to check my...

Discharge in a DC RC circuit and Kirchhoff's Loop Rule]]>

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It shows Vg but not Vf. It mentions some equations at the bottom. Does anyone know how much is Vf for 0.1bar?]]>

Bernoulli's equations expresses the conservation of mechanical energy for a particular fluid parcel moving inside a time-independent flow. The parcel is restricted to move and remain along a particular streamlines. The sum of the trinomial is equal to a constant on every...

Bernoulli's equation, different streamlines, and wings]]>

Rate of water flow into an immersed container]]>

Rifle recoil question...]]>

Viscosity ##\mu## is a "measure" of the momentum flux

Thermal diffusivity ##\alpha## is a "measure" of the heat flux (kinetic energy of molecules)

In gases both...

Viscosity and thermal diffusivity in liquids and gases]]>

I was responding to a post on a different thread that claimed you could make a tunnel around the Earth and if you sent a...

Escape Velocity and Centripetal/Centrifugal Acceleration]]>

Phase difference in a transformer]]>

Which side should face the laser in these two cases?

I know that the...

Plano-convex lens, which side should face the laser source]]>

Due to relativistic effects, its total kinetic energy will be 1.44 E+36 Joules (Lorentz factor = 3.2 E+11).

A hypothetical particle...

Help me find my error in a relativistic kinetic energy calculation]]>

Something like a text file or CSV file from a public source?

Also looking for Germanium - the same spectrum.

Any suggestions where I could get this?]]>

To measure the energy density of a (brief) laser pulse]]>

Particle accelerators and Casimir effect]]>

I have begun reading the Feynman Lectures to repeat the most important ideas from my undergraduate studies and to improve my intuitive understanding of physics.

In one of the first chapters, the one about the conservation of energy, he demonstrates that the conservation of energy is...

Feynman: Reversible machines, no perpetual motion?]]>