A point mass m= 20 kg, is suspended by a

massless spring of constant 2000 N/m. The

point mass is released when elongation in

the spring is 15 cm. The equation of

displacement of particle as function of time

is : (Take g = 10...

Spring, SHM]]>

View attachment 224416

m:mass of solid cylinder

T: tension in string

w:angular velocity

m(g-a)=T

mg-ma=T

a=v^2/r=w^2r

now what?]]>

View attachment 224357

I am considering the two rods separately .Considering QP alone EMF induced will be (1/2)Bωl

Bent rod rotating in a magnetic field]]>

Which Vectors Can Legitimately be Broken into Components?]]>

This question is referring to the classic ball in a loop question where it is dropped from a height and slides into a loop de loop. View attachment 224308

Derive an expression in terms of theta the velocity of the ball at...

Circular motion - ball in a loop]]>

(First of all, I want to clarify what's my stance on all of this, I'm not a proponent of these ideas; in fact, I'm always sceptical...

Are these models true or even relevant?]]>

Thanks]]>

If the height of a frictionless incline is h. Determine the work done by the force due to gravity F as the crate of the mass m slides down the incline

W=Fd cos (theta )

Force due to gravity...

Determine the work done by the force due to gravity]]>

If the Green's function of the electric field in a system is

[tex] G(x,x')=e^{-i(x-x')^2}[/tex]

I want to calculate the phase of the electric field at [itex] x [/itex] if the source is uniformly distributed at...

Order of multi variable integration of infinite range]]>

The minimum delta-v required to circularise the orbit of a projectile that has been fired horizontally from the Earths surface at a given velocity.

Completely ignoring atmospheric drag.

See the attached spreadsheet.

The steps are...

Orbit circularisation/insertion spreadsheet]]>

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]]>

so I was going over my notes on classical mechanics and just started to review rotation matrices which is the first topic the book starts with. On page 3, I've uploaded the page here

The rotation matrix associated with 1.2a and...

Possible error in Marion and Thornton's Classical Dynamics?]]>

This thread is for showing your images of solar activity taken with YOUR cameras, telescopes etc.

That is, don't post images from SDO, SOHO or any other professional sources unless you specifically want to ask "how do they do that and what are those solar features I can see?

This...

Solar imaging and techniques]]>

So i thought about some other stuff and then somehow this idea appeared to me, now according to physics it is impossible to communicate information faster than the speed of light through vacuum which is "c".

So for any two bodies moving in...

FTL train + FTL communication thought experiment]]>

Dark energy = cosmological constant, any problems with that?]]>

In picture above

impulse = Δp

4.28NS = Δp

4.28NS = p

4.28NS + 0.18kg*0.16m/s =...

Impulse and momentum question]]>

Show that ##\displaystyle \sum_{i=0}^{100} {100\choose i}{200-i\choose 198-i}x^i## is divisible ##(x+1)^{98}##.

I am pretty stumped, but I have a few general. I...

Showing that one polynomial divides another]]>

If all the quantum fields were gone.. and we have only branes left.. do you consider branes as existing in the quantum vacuum or outside of it? Or what...

Quantum Vacuum]]>

Turns out Asperger was a Nazi]]>

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?]]>

For a single mechanical unit lung, assume that the relationship among pressure, volume, and number of moles of ideal gas in the ling is given by P

Derive lowest order (linear) approximation]]>

So this is more of a really vague conceptual question, I'm sorry if it doesn't really make sense. I'm in the stage of learning this where I don't quite understand things well enough to form a proper question.

I'm a little bit...

Heat and Mass Transfer: Nodal Networks]]>

Ask the Advisors: What's Your Most Memorable Textbook?

View attachment 224394

...

Ask the Advisors: What's Your Most Memorable Textbook? - Comments]]>

2. Relevant equations

V

I

For a part

I try to draw 3 mesh...

Simple transformer circuit with 3 resistors]]>

I'd like to get some points on this.

Firstly, by a non...

Non inertial frames in SR?]]>

https://arxiv.org/abs/1704.07685

This suggests the possibility no new theory beyond BCS is necessary.

I’m interested especially in comments by members who work in this or related fields.]]>

Now this will induce charge -Q/2 on the inner plate B and +Q/2 charge on the outer plate B....

What is the potential of plate B with respect to infinity?]]>

The problem is state in the attachment.

None to add.

3. The attempt at a solution

Struggling with this problem because of the phasor part of it. Perhaps this is justified because the angle...

Electromagnetic Radiation of Single frequency Incident on a Slab]]>

two rail cars are coupled together, each weigh 82500 lbs. They are on tracks at a 0.499% grade. each rail car has 2 trucks of 2 wheels each, for a total of 16 wheels. The assumed force of friction for contact with the wheel...

Does the railcar move?]]>

A planet has a gaseous atmosphere with a density of 0.1 g/cm³. The planet itself

completely consists of liquid methane with a density of 0.4 g/cm³ and has a radius of

3800 km. A test balloon is dropped onto this planet, which...

Test Balloon on a planet]]>

Many hot-water heating systems have a reservoir tank connected directly to the pipeline, so as to allow for expansion when the water becomes hot. The heating system of a house has 63.1 m of copper pipe whose inside radius is...

Thermal expansion of a copper pipe]]>

What cases of this happening do you find most notable, what showed that the hints were...

What false hints of new physics were most notable?]]>

I am currently involved in atmospheric remote sensors on board a satellite which collect back-scattered and reflected solar radiation to provide atmospheric composition measurements through an algorithm based on Differential Spectroscoy. I am currently involved in studying the physical...

About atmospheric remote sensors]]>

I have found a very interesting discussion at...

Equations: whiteboard vs slides]]>

Find ##\langle x \rangle## in the momentum representation

I am having trouble understanding some of the steps needed to get to the expression, assistance is greatly appreciated!

3. The attempt at a...

Position mean in momentum-space (QM)]]>

Neural Nets in AI]]>

Die average kinetic energy and impuls squared of a single molecule are:

$$<E_{kin}>= 6.5*10^{-21} J$$ and $$<p^2> = 1.8*10^{-45} kg^2m^2s^{-2}$$

Which gas ist it?

3. The attempt at a solution

Finding the gas based off of mass]]>

14 bananas and pears were bought in total by John from the supermarket.

The total cost was £1.52

if Banannas that John purchased cost 5p more than pears, how much did John buy from each fruit?

Diophantine equation]]>

I'm trying to calculate the pressures exerted back on a piston by a working hydraulic fluid in a damper system. I've attached a drawing of the system and the equations I'm using. Essentially the piston motion is restricted by flow through an orifice. I have data for the flow rates...

How to calculate the pressure on a piston in a damper system?]]>

My answer is 16/25 of 1ke but while deriving this answer I simply solved based on the question as...

Maximum amount of energy the neutron can lose]]>

I have been in university for over 5 years now (switched major from IT to computer engineering) and I want to get my degree finished. I have saved up enough money to go to school...

If you were me, how would you approach my future?]]>

A First Idea of Quantum Field Theory - 20 Part Series

View attachment 214213

...

A First Idea of Quantum Field Theory - 20 Part Series - Comments]]>

I’m not as smart as I thought]]>

Is Shear Stress Vertical or Horizontal in I-Beam Webs?]]>

Either the Sun Is Getting Smaller or Gravity Is Getting Weaker

View attachment 223610

...

Either the Sun Is Getting Smaller or Gravity Is Getting Weaker]]>

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?]]>

1) Why measurement appears to cause a discontinuous change in the wave function for a single quantum entity/system?

As in Schrodinger, "The abrupt change by measurement … is the most interesting point of the entire theory…in the realism...

Measurement problems?]]>

SuperKEKB is...

SuperKEKB/Belle II start up]]>

There is a block of known mass

Pulley and circular motion]]>

I'm trying to determine the torque vector and quantity of said vector per the sketch attached.

T=fd

T = 100 lbs x 2 f2f

T= 200 ftlbs

But my real question is...

Moment Arm Question]]>

A particle moves along a circle in a region of uniform magnetic field of magnitude B=4.0 mT. The

particle is either a proton or an electron. It experiences a magnetic force of magnitude 3.2x10

What are (a) the...

Charged particle motion in a magnetic feild]]>

Does anyone know the answer?]]>

Short background on me. Went to college at 15 and was far too immature to excel. Ended up squandering my early possibility of higher education and then joined the military young. After years of that I am back in school and have finally chosen a direction. As a small child I...

New guy]]>

Concept behind equivalent metrics]]>

Kinetic energy per mol is 3/2KT

Q = nC##\Delta##T

U = Q + W

W = -P##\Delta##V

1) internal energy = 3/2NKT

2) heat needed to increase temperature of 1 mol ideal...

Heat and work when temperature increases by 1 degree]]>

I would like to go to some year in the 60s, to some city in my country just to see how more quite and peaceful it was and to contrast how many people there are today and back then! For...

If you could live back in time...]]>

Reaction engine concept]]>

I was reading a paper that outlined various ways to approach solving dynamic problems. The first approach outlined by the author is D'Alembert's principle of virtual work. In describing...

Body force vs Inertial force]]>

Then space started expanding, thus increasing the distance of any 2 points of that infinite dense matter, thus making it less dense...

Did cosmic inflation happen everywhere in the Universe?]]>

How to hook up my PC to my TV]]>

Eigenproblem for non-normal matrix]]>

I am trying to learn more about this field. Whether you work or have worked in this area or not, I would like to know where Soft Matter is going in terms of theory and applications.

Thanks,

A.D.

*I apologize in advance if there are already many threads specifically addressing this...

The Future of "Soft Matter Physics"]]>

I ought to see some movies with Immortality themes as I ponder on my own immortality.. what have you seen that is the...

Sci Fi immortal movies]]>

My query is that...

As one can see that in the IF response curve the picture carrier is placed 6db down the amplitude curve. Such a placement modifies the output of video detector in such a way that the picture carrier lies at half point or 50 % of the total amplitude.

Now this whole...

6 dB of IF response curve...?]]>

if a beam fixed at two points is on an angle say 45 degrees from the x or y axis instead of running parallel to x axis in most questions does this effect calculations? The force acting upon it would be a load directly downwards...

Does the angle of a beam fixed at two points affect the method?]]>

Lets say I have N independent, not necessarily identical, random variable. I define a new random variable as

$$Y=Σ^{N}_{i=0} X_{i}$$

does Y follow a normalized probability distribution?]]>

I have just finished up my sophomore year as an undergrad pursuing a major in Physics (and the accompanying minor in math). I know that it is common for physics majors to minor in computer science or programming, engineering, sometimes bio or chem, and others. However, I am...

Help: Physics major minoring in Spanish]]>

I just bought a new 7th gen I5 laptop. I am trying to load an old Adobe photoshop 6.0 I bought 18 years ago. It is a legitimate copy I paid $600 back in the days, I have all the serial numbers and all. But it won't install. I have read through a lot of suggestions on web. One problem is...

Help installing old programs onto new a Win 10 computer]]>

Question attached:

View attachment 224393

Hi

I am pretty stuck on part d.

I've broken the fields into real and imaginary parts as asked to and tried to compare where they previously cancelled to the situation now- see...

QFT, Noether and Invariance, Complex fields, Equal mass]]>

The very talented 21 year old Norwegian singer and songwriter Sigrid:

...

Favorite songs (new thread)]]>

1)There are two gluons and one photon attached to the internal line so this is 3 coupled vector current insertions...

Applicability of Furry's theorem]]>

question attached-

I am stuck on some of the reasoning as to why we set ##B(r=0)=0##

View attachment 224390

please not as described in the attempt I am interested in the concepts and have not posted my solution to A,...

GR Cone Singularity]]>

What would the resultant force have been at the instant of release, if a 350 g mass were suspended from your spring, pulled down 3 cm and released?

What would have been the instantaneous acceleration at the moment of release?...

Resultant force of spring at the instant of release?]]>

Material testing machine]]>

In an effort to get the students in my Advanced Physics class to rely less on calculators and to develop their math skills, I am going to give them the option of using slide rules this year. I am offering them a small bonus on tests if they use slide rules instead of calculators....

High school physics teacher seeking slide rules]]>

Suppose that I have some cells that produce a...

Propagation of Error when Taking the Average of Averages]]>

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

Pyrroles from urochrome?]]>

View attachment 224339

Two speakers A and B, 2.00 m apart, produce a sine wave at the same frequency and phase. A microphone is placed on the line BC perpendicular to AB, at a distance x from B. The speed of sound is...

Frequency at which no destructive interference occurs]]>

PhD rankings and employment]]>

[Firstly, I didn't know if this belongs here or in General; please move if appropriate].

<Moderator's note: moved to GD>

I was reading this paper on...

Sacks' Autistic Twins and Prime Testing]]>

I have a little doubt that i want to clarify.

If I am sitting in a stationary train, having a ball in my hand, the ball will remain stationary relative to my hand and plateform. Now if the train starts moving, again the ball is stationary...

Constancy of the speed of light]]>

Find a piecewise smooth parametric curve to the astroid. The astroid, given by $\phi(\theta) = (cos^3(\theta),sin^3(\theta))$, is not smooth, as we see singular points at 0, pi/2, 3pi/2, and 2pi. However is there a piecewise...

Find a piecewise smooth parametric curve to the astroid (a hypocycloid with four cusps)]]>

$$\int_0^\infty dx \: e^{-iax} - e^{iax}$$

I know that this does not converge for many reasons, but most obviously because I can rewrite it as

$$2i \int_0^\infty dx \: sin(ax) = -2i a [\cos(ax)]_0^\infty$$

which does not converge to anything.

However the book...

Getting a finite result from a non-converging integral]]>

and also have done a master in condense mater and nano-science

i worked on noble solid /amorphous interface in my first master internship ( DFT and

New member and enthusiast to share my experience and learn]]>

Newton's first law states that an object in motion will remain in motion with a constant speed unless an external force acts upon it. If the expansion of the...

External energy source?]]>

Attached

View attachment 224367

Below

To be honest I was going to differentiate one equation to get a 2nd order ODE and plug in the other equation,...

Mathematical Biology- Coupled ODEs]]>

I am integrating the following

Code (Text):

sin\[Theta][x_, \[Alpha]_] := Sqrt[(2 - 2 x^2)/(

3 - 4 x Cos[\[Alpha]] + Cos[2 \[Alpha]])]

cos\[Theta][x_, \[Alpha]_] := Sqrt[(Cot[\[Alpha]] - x Csc[\[Alpha]])/(

1 + 2 x Cot[\[Alpha]] Csc[\[Alpha]] - 2 Csc[\[Alpha]]^2)]

\[Rho][x_, \[Alpha]_] :=...

Prove that ## L ## is non-regular language.

View attachment 224379

2. Relevant equations

none

View attachment 224375

View attachment 224376 ...

Non-Regular Language, Pumping Lemma]]>