Centrifugal force in plasmas]]>

Difference between charge and charge density]]>

Is this solved, or any new ideas about it?]]>

trouble with Humboldt H12090 aspirator vacuum pump]]>

Effects of Ultrasonic Transducer in contact with glass]]>

Will 2 magnets lose energy while repelling each other?]]>

Tension (and Frequency) with Change in Temperature]]>

Question about the Hamiltonian and the third law of thermodynamics]]>

Envisage a large circular container with a central power driven agitator. Two cylinders are attached . The whole...

Dynamic pressure variances in sealed and pressurised systems]]>

Planarity of Central Force Motion]]>

My IA is about bungee jumping where I increase the mass and look at the efficiency of energy at the lowest point of the jump.

My question is: How do I find the spring constant k for an elastic cord? I need it so I can plug it into the elastic potential...

Help with IB Physics IA about bungee jumping...]]>

I know that

and

Why velocity can change when angular momentum is conserved?]]>

We know that growth decay function is ##N_{t}=N_{0}\times e^{\lambda t}##. Exponential part is positive as this is a growth function.

Is the function...

Decay/growth function]]>

A follow-up...

Penning Trap questions -- capacity, manufacturers, leakiness...]]>

**What causes tension in a rope/string(i think its related to electromagnetism, but i am not getting the clear idea...**

A few questions related to tension in a string]]>

Upwards forces in car crashes]]>

In an isolated composite system of two paramagnetic system:

System a with ##N_a## spins and a magnetic field ##H_a ##

System b with ##N_b## spins and a...

[Stat Phy] What does exhausting the states of a system mean?]]>

First stop should be our very our PF Insights blog which hosts many physics tutorials...

Physics Learning Resources]]>

It is known that ordinary cameras can make infrared radiation which comes from remote controls visible at their own display. My question is about the explanation of this fact. Is the electronic process simple to describe? It seems that the infrared can produce photocurrents which are...

Cameras detecting Infrared and making it visible]]>

In my physics textbook it says that ammeter in circuit C shows higher current than ammeter in circuit A and D.

And the voltmeter shows higher voltage in D than in B, and C.

It's explained in the book that way: some electric current is passing through the voltmeter...

Why you can't measure voltage and current at the same time?]]>

I was going through some video lecture (Quantum Mechanics) when I encountered a definition of momentum as shown in the attached picture.

I do not understand how iota and ħ is ignored ? There are some negligible terms after plus sign. What are those ? In short how they have...

Definition of Momentum in terms of a partial derivative]]>

What if everyone on Earth starts bursting crackers for one day?]]>

I am not sure my question will totally make sense for those of you who now this topic well but as I am new to it I hope I can be forgiven.

My problem is to work out how much water will condensate as a stream of moist air is expanded through a turbine.

So far I was using Antoine's...

Saturated VapourPressure of Steam above Critical Temperature]]>

Barrier of Diffraction: Different Wavelengths, Same Color?]]>

For some time now, I have been looking online for a relationship between temperature and magnetic flux density of a ferromagnet; below the Curie point. However, I can't seem to find any relationship or formula. Do any of you know...

Temperature and magnetic flux density]]>

Spiral circular motion]]>

Did you guys know about floating solar panel? So, im gonna make a product that will float and can support the solar panel (20kg). And know im in the calculation stage, so i need to know, that my product can :

1. Float

2. How much weight of my...

Moving objects on water (floating solar panel)]]>

This is a non trivial conversion. Please feel free to correct me:

The primary radiation source is Cesium 137 -- it's a gamma...

Radioactivity exposure...]]>

If...

Why is binding energy called binding energy?]]>

Magnetic field vs gravity]]>

A force acts on the card which is greater than the static friction acting between the card and the coin. Hence the coin is able to overcome that....

Penny on a card experiment.... explanation]]>

Question related to inertia and non inertial frame]]>

In electromagnetic units:

##F_{dyne}=\dfrac{p^2}{r_{cm}^2}=\dfrac{1^2}{1^2}=1 dyne##

where ##p## is pole strength in emu

In SI units:

##F_{N}=k_A \dfrac{P^2}{r_m^2}=10^{-7}...

Why am I getting two different results in emu and SI unit?]]>

So the path integral is Integral of H dot dl = Current Enclosed

Why, in this video, does the...

Why isn't path integral of H-field 0?]]>

Is gravitational constant unchanging over age of universe?]]>

methane (CH

carbon dioxide (CO

butane (C

Phases of hydrocarbons in a compressed gas cylinder]]>

In N side there are free electrons. In the positive charged side of the depletion region, there are...

A couple of questions about diodes and the depletion region]]>

$$\left(\frac{\partial P}{\partial T}\right)_V = -\left(\frac{\partial P}{\partial V}\right)_T \left(\frac{\partial V}{\partial T}\right)_P$$

where does the minus sign come from?]]>

What is this angular frequency? Why do we use ##\omega## rather than ##\nu##, that is, the normal frequency? All equations in S.H.M. are made with ##\omega##...

What is the need of angular frequency in S.H.M.?]]>

There is 1 point defined to have 0V, and another point has exactly 1V. Assume there is nothing else in the universe.

https://i.imgur.com/iv9oL5j.png

How do I find the electric potential and...

How to find electric field given points of electric potentia]]>

In the given question part (a) I dont understand why the work done is negative? The answer says that the displacement is along positive x direction (i understand that) while force acting on the particle is along negative x direction ( why is that? since it...

To calculate work done from a graph]]>

Consider the picture above. The ring is being pulled down the incline with a force of mg*sin(θ). If you analyze the system about the...

Static friction does no work?]]>

is there a possible or a certain arrangement of prisms , lenses and mirrors that can be made in order to combine numerous less...

Combine lasers to make a single strong beam]]>

The velocity is a constant ##u_e## everywhere except in a boundary layer over the plate, where the velocity is a function of distance...

Please verify integral and approximation, boundary theory]]>

Simple cheap method of measuring mass distribution of object]]>

I would like to know why it´s so difficult to find information about the generation of fringes in a one slit interference experiment in a water tank.

Best Regards,

DaTario]]>

Reduction in the number of wheels means less drag?]]>

Why does the car skid when brakes are applied too hard?]]>

So my question is if I have a 2 foot tire iron and I am torquing my nuts. Lets say they...

Torque and force on a tire iron]]>

Could you please help me with the queries below? Thank you.

Please have a look on this attachment. In the given attachment, the disk is mounted vertically...

Some questions about electromagnetism]]>

During day there is a positive sensible heat flux and sensible heat moves...

Negative Sensible Heat Flux at Earth's Surface]]>

First, let me introduce myself:

I m from Brazil, I studied physics a few years ago and I ended up leaving the course, today I work with software development.

I would like to know if you can help me to take a doubt:

I came up with an idea that an electron could move so fast that it would...

Idea / doubt about the movement of electrons]]>

Why is linear momentum not conserved or realistic here?]]>

I have posted on Physics Forums a few times in the past, but mostly for help with my old physics classes and not anything in the real world. Part of my work involves radiography, but it is generally done in a field environment where we just shut down large sections of land to safely...

Inverse Square Law with Half Value Layers for X-Rays]]>

Cutting magnets]]>

For example:

1) Properties of the fluid:

1)Velocity: My professor said that the lower the velocity the more time the fluid gets to interact...

Logical explanations of factors, Heat transfer coefficient]]>

https://arxiv.org/pdf/1710.02105.pdf

which I like to bring to notice.

I haven't figured out why space is usually described in terms of only 3 spacial dimensions rather than six: x,y,z, Tx,...

Why does physics consider only 3 of 6 dimensions]]>

Train Conservation of Energy Question]]>

I didn't understand the following:

The relationship between ##V_{CE} ## and ##I_C## is linear.

View attachment 212844

In active region, even if the ##V_{CE}## increases, ##I_C## remains almost same for a given ##I_B##. So, how can the relation between the...

BJT Load - Line]]>

Only, I know the volume isn't lost, the fluid (being incompressible) will exert pressure on all...

Internal pressure due to vessel collapse]]>

1. Papers

Recent Noteworthy Physics Papers]]>

The book says that all quantities in eq. 14.17 are state- functions. How do we know that?

Earlier I read that both W and Q are not state functions.

Now, since S is state-function, it means that tem. is not a state- function, isn't it?

Does it mean that for a...

DU = TdS - p dV is valid for irreversible process -- Proof]]>

The problem involves the density of a liquid, the density of a solid, and the height where the solid will be released in the liquid, gravitational force, and the time it takes to reach the top of the...

I need help, been a while -- density of a liquid, the density of a solid, and a height...]]>

Torque and force question]]>

Help me please]]>

TL (dB) = 10*Log (W1/W2)

where

W1 = sound power incident on wall

W2 = sound power transmitted through wall

Based on this understanding of TL, I wish to determine the extent to...

Understanding sound transmission loss (TL)]]>

Intersecting 2 continuous laser in thin air to create a dot]]>

Let's take EM field in a rectangular box with walls that are perfect conductors (optical cavity). EM field distribution inside...

Longitudinal/transverse modes in optical cavity (resonator)]]>

Wave interference - coherence and wavelength]]>

I am confused about the work energy theorem.

If someone goes up the stairs at a constant velocity, is work being done on the person? After all, Wnet = change in kinetic energy, and that change is zero.

This is the original problem that I am trying to solve, from David Morin's Problems...

Question about work energy theorem]]>

How can I calculate horsepower, brake, or torque?

Working on a project,

Thank you,

Larry]]>

Please could someone kindly explain how zero weightlessness is achieved in this aircraft. I have tried to use my own understanding and what I have read online.

My ideas are:

To experience weightlessness the plane must be in freefall so the only force acting on it must be gravity. Since...

The NASA Zero Gravity Flight]]>

When drawing my FBD, I made...

How do you know which way friction points?]]>

Feynman Audio Lectures]]>

I was going through study of gravitation of earth. The book teachs that gravity of earth is more near poles than at equator as earth is not perfect sphere rather radius of earth is lesser near poles larger at equator. A thought came in my mind that if the water at level goes also...

What shape would the Earth appear to have if it were just covered by water]]>

As Wikipedia says "By contrast, the...

Why evaporative cooling is a constant wet bulb temp process?]]>

Radio waves interaction with other electromagnetic waves]]>

From the picture I drew, there would only be a net effect of E-field in the X direction because there...

E-field from uniformly distributed charges on sphere?]]>

Energy changes upon insertion of a solid dielectric in a capacitor]]>

Why does Maxwell's first equation make sense?]]>

While doing research into solenoids I came across the MagLab (The National High Magnetic Field Laboratory) where they place coils one inside another to bolster the field, and reach upwards of 45 Tesla. They use an...

Will a solenoid inside another solenoid increase its strength?]]>

"In the UK, the Reynolds number is taken to be equivalent to:

25 043 x Q/d for natural gas; and

83 955 x Q/d for LPG."

[Q = flow rate, cubic metre per hour, d = pipe...

Can someone explain this equation for Reynolds' number?]]>

Say we have a rocket of...

100% energy efficient, constant power rocket]]>