a black body is one that absorbs radiation of ALL wavelengths and reflects NONE. Therefore it appears black at low temperatures. And when heated it emits radiation of all wavelengths making it appear...

Perfect Black body]]>

But Jupiter's gravity is more than the Earth's gravity, although its density is lower?

Is the sun's gravity more than the Earth's gravity, even though the intensity of...

What is the relationship between gravity and density?]]>

According to my design, the total amount of space in the chambers would be approx 50 cubic inches (0,0861 cu feet). Then to reach a required 400 cfm it would...

Force required for small blower motor]]>

View attachment 224463

Simple circuit, 1 bulb and X amount of batteries. So...

How many batteries does it take, to light this bulb up?]]>

My cell phone and the base of the service communicate with each other because...

Time travel and resonance]]>

I had a lot of fun, and I am looking for...

What is the thickness of the atmosphere?]]>

Here is the shadow of the edge of a screen. This picture is in one of Mr Feynman's books. (Http://www.feynmanlectures.caltech.edu/I_30.html)

Of course, there is light interference in the edge of the shadow. It's normal. It's diffraction. Mr Feynman...

Direction of light]]>

Bending light with temperature gradients]]>

Intensity as light passes through two quarter-wave plates?]]>

This dumb video is making the rounds of the dumb.

Apparently, it's not enough to promote that water goes down the drain in different directions in different hemispheres, but now apparently, you only need to go

More rotating toilet bowl insanity]]>

We basically have a ball made of 20Kg of "person".

And it it accelerates at 1.8*10^5 m/s² for 1/30 of a second reaching 6000 m/s...

How absurd are these numbers really?]]>

Why do rockets turn horizontally so soon after launch?]]>

First off, i would like to apologize for any spelling errors. I am Portuguese and my english is going to be very simple.

I am in the process of building something and i am reaching out to the physics community for help solving a problem.

I am a CNC programmer and while i was in...

How to control the weight of an object?]]>

Reaction engine concept]]>

Would this work? (air filled tube inside a water filled container)]]>

m*g*sin(theta) = m*v

and this explanation:

Force of gravity along the radial direction]]>

Why did the lid of a heated container cave inwards?]]>

10^9 GeV dispersed collision energy]]>

I am pondering on the airflow around a wing:

When air flows over a wing, part of the air goes below the wing and part over the wing. Even when the air is moving, the pressure at a point in space is always isotropic. The pressure on top of the wing is slightly lower than than...

Pressure and Lift around a Wing]]>

Electric Field of a Line of Charge]]>

What is the underlying reason for stimulated emission?]]>

Does light really do this?]]>

I am unable to understand a certain (important) concept.

We all know what the field lines of a permanent magnet look like. They go from north to south, and curve around the magnet.

This direction (direction of the magnetic field) does NOT describe the direction of a force. And that's...

Magnetic Field Lines & Force]]>

What I know about the body:

Area of the body=20199.04 mtr²

Density of body=985 Kg/m³

Thickness of body= 75 mtr....

Force of a free-falling body]]>

How do temperatures add?]]>

Banked Turns Part II: What Force Causes a Car to Creep up a Wall]]>

When considering the drag coefficient of a rocket in transonic/supersonic flight, I always expected the drag coefficient to peak at exactly Mach 1 due to the abrupt increase in pressure that occurs when breaking the sound barrier. However, I have been looking at several websites and...

When should the drag coefficient of a rocket peak?]]>

Sorry for my English.

I have found on the net a solution of Newton equation. And I just want to have your view.

The speed between two mobiles moving towards each other is: (only with gravitation)

dx/dt = - square root (2.G.(m1+m2).(1/X0 -1/X))

Where X0 is the distance between the two...

Solution to Newton's equation]]>

How do scientists think about scientific theories,...

Incomparable Theories]]>

Centrifugal Force Experienced at the Earth's North Pole]]>

I know that it works for an infinite wire. Does it work for a finite wire? Where does it work and not work?]]>

I'm talking hotter than T = 6000k.

The higher the temperature, the more the curve in the attached figure would shift to the left (while at the same time getting higher).

So the intensity peak would eventually fall back into the invisible portion (very small...

Do hot objects always glow?]]>

In the derivation they proposed that the probability for being at energy e (for A) is proportional to the number of states in reservoir. I didn't...

Deriving boltzmann distribution]]>

The concept of work]]>

Electrons, magnetism and spin]]>

This deals with Lenz's Law.

4 Questions About Lenz's Law Experiment]]>

Why can't we take 'k' as some other value?

I will be thankful for help!]]>

if you need units, yards works.

I'm also curious about how that light...

Lens Math for a Semicircle and Vesica Piscis?]]>

I do know that by first law of thermodynamics, if two people touch each other and if one of them feels...

Heat in crowded places]]>

I don't know how to compute that number, but probably is a kind of reference value...

Q: How many ion-pairs are there in normal conditions* in the air?

(This is not homework, it is just out of curiosity.)

Thank you for your time.

Regards,

ORF

* 1 atm, 300K.]]>

Resultant Force]]>

Please explain the true concept of this scenario. As far as I understand is that Velocity will start decreasing. But I am...

Relationship between Velocity and Acceleration]]>

I find the typical explanation of tornadoes perplexing (that's a polite way of saying I don't believe it). The explanations I've seen claim that tornadoes start out...

Tornadoes and angular momentum]]>

My understanding is that an invariant quantity is a value which does not change regardless of frame of reference it is being measured in.

Covariance is a value which...

Covariance and invariance]]>

How the atom was proven to exist?]]>

Dieletric breakdown of air]]>

So in a nutshell, the equation is more complicated and is in the form of

f^2=aT^2+bT (f is frequency, T is tension, ab are constants involving the control...

Showing/proving a physical relationship]]>

I have a practical question regarding heat transfer within my laptop. My laptop uses a shared-heatpipe design, meaning that my CPU and GPU are connected by a common piece of copper, and then each chip goes off to its own heatsink/fan.

While playing games, I was monitoring the...

Heat transfer within a laptop computer from CPU and GPU]]>

I am a bit confused how to calculate the shear force and bending moment graph for a beam under point loads, distributed loads and bending moments.

Is the discontinuous functions the best method to solve such problems?

Can anyone outline an approach?

I don't understand for example how...

Shear force and bending moments graph]]>

Instrument to measure the frequency of sound]]>

Are all plane waves transverse ?

I'm confused about the difference. I know the difference between transverse and longitudinal waves but i'm not sure on how plane waves fit into the picture ?

Thanks]]>

I've come here looking for opinions and suggestions from a community of people far more proficient in the field of physics than I am, with a topic that is probably a little unusual. The situation is...

Aesthetically pleasing formulae involving time?]]>

What makes a good physics theory]]>

1. Papers

Recent Noteworthy Physics Papers]]>

However, isn't this for an object going around in a circle? Suppose I have a curve (0.0033x

Please note...

What is the fastest speed around a curve?]]>

Simplistically, Why do objects with the highest mass become attracted to the nearest highest mass? Bowling ball falls to earth via...

Gravitation Mass]]>

It's all...

Rotation in 3 Dimensions]]>

Modeling an Einstein solid that is coupled to a paramagnet]]>

Can indistinguishable particles obey Boltzmann statistics]]>

Nuclear Fusion: Electron Thermal Transport Terminology]]>

I am not sure if this is the correct place to ask this question.

When a fluid's pressure gets increased using a pump, does its enthalpy increase too?

Thank you in advance.]]>

Is there any material that is like fabric and can withstand high temperatures maybe 1k, 2k C etc?

I also need it to be waterproof, ie to be able to hold liquid.

Thanks!]]>

To:

I'm confused as to why you add the product of the pressure and volume of...

Comparing delta(PV) vs P(deltaV)]]>

I have a question based in a statement take from

Separation of Fluids in a Centrifuge]]>

I have a question regarding the precise definition of angular momentum in orbital motion.

I see one definition says angular momentum h, position, r, and radial velocity, r_dot, are related as follows:

h = r x r_dot.

However, I also see one definition that says h is related to r and...

Orbital Mechanics Angular Momentum]]>

Is the index of refraction constant for a given medium?]]>

this is what I want: https://i.imgur.com/F6HIYBl.png

this is what I do not want: https://i.imgur.com/ylhMeEa.png

This kind of beam combining can be...

Overlaying light beams by one replacing the other where they intersect]]>

https://docs.google.com/spreadsheets/d/1w9VebhPT0S78buN_33hN0ekUggX26lyB4BVugedR1zM/edit?usp=sharing

I'm hoping to...

Radial Piston Input Torque]]>

There are special cases where there is no HYPOTHESIS.

Can you give some examples of things discovered without giving a HYPOTHESIS?

That is, they do an experiment and they discover something new without a hypothesis?...

Examples of discoveries without a hypothesis?]]>

thanks, if you want to direct me to literature i would appreciate that, what i have in my motors book talks about the hand rule for...

AC magnetic field and how an electric motor works...]]>

Reflection from a small spherical mirror]]>

Working in a Vacuum & zero gravity]]>

Jump conditions for electric field across an interface]]>

Why isn't

For some reason the integral sign is...

Faraday's Law--Confusion about terms in the integrals]]>

What do you think could have caused this resistance?

View attachment 223498 ...

Hot metal lid on cool surface has resistance when pulled up]]>

So would it take more energy to take out water at the top of the straw from the thinner straw?

Or would, due to gravity cancelling eventually the capillary rising, the adhesive force at the very top of the straw is...

Adhesive forces]]>

Pulling/pushing an elastic rod at high speeds]]>