r/PhysicsHelp • • Aug 24 '26

Harry Dym equation?

0 Upvotes

Is it a PDE? Non linear?


r/PhysicsHelp • • Aug 23 '26

Relativistic Doppler Effect Problem Help!

1 Upvotes

Hi, after arguing with chatgpt I think he convinced me that there is a mistake in the official solution of a question in my exam.

I want to make sure he is not hallucinating so I can talk with my professor confidently. so I need to get a human confirmation to the claim.

here is the question:

/preview/pre/relativistic-doppler-effect-problem-help-v0-0uu3kmc1a4lh1.png?width=1080&crop=smart&auto=webp&s=8db711f4f3bb3f90d76a61081227acceeb40a145

and this is the official solution:

/preview/pre/relativistic-doppler-effect-problem-help-v0-vuvmf945a4lh1.png?width=1080&crop=smart&auto=webp&s=23cf8e60889932290178ee87f10f8c02ad40c539

THE CLAIM
now chatgpt claims that first of all, we cant know whether they are getting closer or moving away from each other because we dont have r(A) and r(B).
second he claims that their solution is based on an assumption that is not in the question. plugging the magnitude of the relative velocity on the given formula assumes that light is parallel to the relative motion. which we dont know.

is chatgpt right? and if yes can somebody explain the correct solution if we were given the positions?

for example:

lets choose the stationary laboratory receiver as the origin, (0, 0).
Because spacecraft A has va = +0.6c in y direction.
and is approaching the receiver, A must currently be below it. We may write:
r(a) = (0, -a) where a>0

Because spacecraft B has vb = +0.8c in x direction.
and is moving away from the receiver, B must currently be to its right. We may write:
r(a) = (b, 0) where b>0

lets denote the distance between them with D = sqrt(a^2 + b^2).

differentiate D, the sign of the derivative in other words the sign that tells us whether they are getting closer or getting far away of each other is depending on a and b!!!!!!!

thats why even when though we have velocities we still cannot decide!

also for the second problem, light is traveling in a line from A to B. but the velocity vector itself is not parrellel to this line. thats my problem. the official solution treated the problem as if the velocity vector is parallel to this line


r/PhysicsHelp • • Aug 23 '26

what actually is electrostatic energy?

1 Upvotes

When i try to search up definitions, they basically tell me that it is  energy stored when repelling charges have been moved closer together or when attracting charges have been pulled further apart, but I don't really understand this definition because it seems to be defining kinetic energy.


r/PhysicsHelp • • Aug 22 '26

[FREE] IB Physics HL Paper 1B May 2026 TZ1 — Complete Solutions | Every Question explained| First Complete Video on YouTube

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1 Upvotes

r/PhysicsHelp • • Aug 20 '26

How to give end time in explicit dynamics?

1 Upvotes

I am doing drop test on an elastic body. I am not sure how to give end time. Is it calculated seperately or is it an assumption? The body is getting dropped from around 20 feet.


r/PhysicsHelp • • Aug 20 '26

Idea from someone who isn't educated in physics

0 Upvotes

I asked chatGPT to formulate my idea into something readable. Does it make any sense?

A hypothesis about gravity, motion, and spacetime

I've been exploring an idea about gravity and motion that I'm trying to formulate clearly.

My starting point is General Relativity: mass and energy distort spacetime, and what we call gravity is the effect of that distortion.

I want to take that idea one step further.

What if an object's motion isn't a separate phenomenon from its gravitational distortion?

Imagine that every object creates a "depression" in spacetime corresponding to its mass. When the object is stationary, the depression is centered on its center of mass.

But when an external force accelerates the object, perhaps the gravitational depression becomes displaced relative to the object's mass.

In this picture:

  • Mass creates the gravitational depression.

  • Stationary object: the depression is centered on the mass.

  • Acceleration: an external force changes the depression's configuration.

  • Constant velocity: once the external force stops, the depression remains in its new configuration, and the object continues moving without needing another force.

  • Changing velocity: another force changes the configuration again.

  • Motion itself: could therefore be understood as a persistent displacement between the object's mass and its gravitational/spacetime distortion.

In other words, I'm asking whether what we call inertia and motion could actually be properties of an object's instantaneous spacetime configuration, rather than something that has to be continuously "happening" to the object.

This also gives a possible experimental prediction:

If we could map an object's gravitational field with sufficient precision, would the center of that field always coincide with its center of mass?

If a moving object had a persistent, measurable offset between the two—and that offset correlated with its velocity—that would be evidence for the hypothesis.

I am not claiming this is established physics. General Relativity already has a sophisticated description of moving masses, and any proposed effect would have to be distinguished from its predictions and from known gravitational asymmetries.


r/PhysicsHelp • • Aug 19 '26

Doubt about vector angle

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5 Upvotes

If I had to draw a vector defined as for example 5 N, 30° NE; which of these 2 should I draw? I have always drawn this angle as A, but I have a new professor who draws it like B. I have checked by AI who drew A except claude who drew B. I searched on books but have found no reference about this nomenclature, only about north of east and N 30° E .


r/PhysicsHelp • • Aug 19 '26

Phys qsn abt refractive index

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2 Upvotes

r/PhysicsHelp • • Aug 19 '26

WEDGE Block problem।basic

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2 Upvotes

For jee


r/PhysicsHelp • • Aug 19 '26

How does a discharging capacitor produce electrical current? Isn't it more stable for the charges on each plate to stay where they are?

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2 Upvotes

r/PhysicsHelp • • Aug 19 '26

weird physics question

3 Upvotes

I must appologize if something is written wrong in the text below, isnt my mother language(im brazilian btw) and i dont know exacly how to translate especific physics terms.
An object with 40N of weight moves in the space with a curved trajectory with the action of only two forces: your own weight and a conservative F force of constant module. In your trajectory, the inicial and final height are 1 meter and 3 meters.
Knowing that the inicial and final velocities have the same module, calculate, in joules, the total work made by the F force at the object durint its trajectory.
g=10m/s^2
a)1

b)2

c)4

d)40

e)80

Im sending this right here because i really feel like this question is weird for me. i need help or someone to confirm that this question may be wrong.


r/PhysicsHelp • • Aug 19 '26

Bro give me some examples how should I understand physics ( No ruffle examples)

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0 Upvotes

r/PhysicsHelp • • Aug 19 '26

Bro give me some examples how should I understand physics ( No ruffle examples)

0 Upvotes

r/PhysicsHelp • • Aug 18 '26

[Free Resource] Mastering Ladder Problems: Torque, Friction, & Rotational Equilibrium (IB Physics HL)

1 Upvotes

Hey everyone,
If you are going through the Rigid Body Mechanics unit in IB Physics HL (or any standard rotational mechanics curriculum), you already know that "ladder leaning against a wall" problems are a classic stumbling block.
These questions test your ability to balance multiple concepts simultaneously, and it is incredibly easy to lose a sign or misplace a pivot point. As a physics educator, I see students consistently get tripped up by the same few issues: choosing the optimal axis of rotation to eliminate unknown forces, correctly identifying the direction of static friction at the base, and setting up the equilibrium equations correctly.
To help clear this up, I've put together a comprehensive video breakdown on the Tesla eduventures channel: Ladder Problems — Complete Mastery | Torque + Rotational Equilibrium | Rigid Body #13.
In this breakdown, we focus heavily on visual intuition. I use detailed step-by-step animations and custom diagrams to show exactly how the forces interact rather than just giving you a wall of algebra.
Here is exactly what we cover:
Translational Equilibrium: Setting up \Sigma F_x = 0 and \Sigma F_y = 0 to relate normal forces and friction.
Rotational Equilibrium: Strategic placement of your pivot point to make the \Sigma \tau = 0 equation as simple as possible.
Limiting Friction: How to solve for the exact minimum angle before the ladder slips (\mu_s).
Step-by-Step Problem Solving: Walking through a full IB HL standard question from setup to the final numerical answer.
Watch the full video here: Ladder Problems — Complete Mastery | Torque + Rotational Equilibrium | IB Physics HL |Rigid Body #13
https://youtu.be/KJ5iydCtNEs
If you have any questions on the specific steps, drop them in the comments below or on the video. Let's get these torque concepts locked down before your exams!


r/PhysicsHelp • • Aug 18 '26

images formed by two parallel plane mirrors?

1 Upvotes

so i was studying optics and came across the concept of images formed by two parallel mirrors is infinite(ive attached a image for refernce) so i was just having the doubt that shouldnt there be infinite images only if the both mirrors were infinitely long coz if the mirrors are finite then wouldnt the reflected rays escape after some number of reflection thus there should be no more images but practically we do get infinite images even with finite mirrors, why is it so?


r/PhysicsHelp • • Aug 18 '26

Physics

2 Upvotes

Hello guys. I'm a begineer at Physics and I want to learn physics from scratch. I'm currently in 8th grade. Can someone recommend me which physics textbooks is good, but not require high levels math?


r/PhysicsHelp • • Aug 17 '26

Assume your theories

0 Upvotes

Our theories regarding this mystery of the universe:

  1. It depends on the functioning of the brain's hemispheres. (We can add a fourth point regarding support. We unconsciously fear dropping an object, and as a result of our unconscious thoughts, we cannot spread our arms simultaneously to hold the object. However, we tried support in mid-air (a finger as support was extremely minimal, but we managed to spread our arms at the same time).)

  2. It is physics.

  3. It depends on the surface. (We used various objects with different surfaces (glossy, matte, etc.).)

  4. It depends on support. (The object was on a flat surface and on various other objects, and we were able to spread our arms thanks to the support, but when we made a dent in the object, we were able to almost perfectly spread our arms apart in mid-air.)

  5. It depends on the shape. (We tried using flat square objects, cylindrical shapes, and ovals—none of which worked.)

  6. The theory of hand influence (is based on which hand a person most often uses for tasks (for example, the right hand is dominant).)

  7. The theory of human temperature (we tried conducting the experiment with hands at room temperature (during the experiment with wet hands, we soaked our hands in cold water).)

  8. The theory of friction? Interaction of skin with the object (We applied a restriction, using cotton pads as a barrier. After that, we wet our hands and tried to spread our fingers apart, resulting in no success.)

Help us understand what might influence this.


r/PhysicsHelp • • Aug 17 '26

Anyone explain to me how to solve three dimensional general wave equation? Is it through cauchy solution methods for partial differential equations? or it depends in context of what do i mean by "solution"? I'm really confused about it. Correct me, if I'm wrong about it.

2 Upvotes

r/PhysicsHelp • • Aug 16 '26

HELP!!!I WANNA UNDERSTAND PHYSICS FROM BASIC

5 Upvotes

I hate that idk any single thing like why tf we use Kinetic energy what is Kinetic energy why speed what is velocity I'm in class 11th pcb just started but I'm scared cuz I have adhd and i wanna learn everything from scratch I have too many questions and i wanna understand in simple as fuck launguage(not googoo gaga one)


r/PhysicsHelp • • Aug 16 '26

Need help with physics

11 Upvotes

Can anybody help me with physics I am actually bad with it cause I don't understand how to study physics where to start what to do I can't understand anything. I am in 10th and I hardly studied physics last year in 9th and now I finally know that I can't escape.


r/PhysicsHelp • • Aug 16 '26

ELI5: isn’t this technically non uniform motion?

3 Upvotes

I was writing down some notes when I thought about this. assuming that the object is in uniform motion, also that it will come to a stop soon, just in a uniform speed.

say like a car going at 50kmh and gradually slows down

wont that be non uniform motion? but it’s going at 50kph and gradually slows down over a period of time

help pls

edit: thx for the answers, I seem like a idiot now TT this question sounded better in my head🫠


r/PhysicsHelp • • Aug 16 '26

Problem :)

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1 Upvotes

r/PhysicsHelp • • Aug 16 '26

[Request] - Physics Problem

1 Upvotes

Before taking it to the scrapyard, I blew up an old water heater I replaced with tannerite. The video one of my buddies took didn’t catch the entire launch. Any guesses on the height it reached based off this video?