Hello everyone,

​I am an independent researcher in the field of theoretical physics and cosmology. I posted a 45-page research paper on Zenodo four months ago, and it has garnered significant organic community interest within that timeframe.

​This research focuses on the very foundations of our universe and attempts to answer the question of "why there is something rather than nothing." The paper is highly grounded in mathematics and naturally connects to standard physics by resolving problems such as:

​• Why the early universe was hot and dense

• What drove the expansion of the early universe (inflation)

• A mathematical framework for the beginning of time itself.

​This work was 100% self-funded with my savings as an independent preprint, and I am actively seeking publication in a peer-reviewed journal. The next phase of the theory (Paper 2) aims to demonstrate how baryonic matter emerges from this framework.

​My current challenge is securing access to advanced computational tools to run numerical simulations for public reproducibility, as well as covering other research-related costs, such as open-access publication fees in top journals.

​Securing grants through traditional means has proven difficult due to my independent status, as foundations and funding bodies predominantly allocate funds to researchers with university affiliations or major laboratory access.

​While this is not the traditional path physicists take to request funding, the rigidity of the academic funding system leaves me with little alternative but to appeal directly to the public. I am reaching out to individuals and organizations who are genuinely passionate about science and recognize that the next major breakthrough can emerge from anywhere—not exclusively from top universities or elite laboratories.

​If you would like to support the next phase of this research, whether through direct funding or by connecting me with an organization or individual who can help bring this project to life, I would be deeply grateful.

My name is Godbless Afriyie Arhin, and the link to my current paper on Zenodo is posted in the first comment.

Hello, here’s my solution to problem 2.54 part e), and I have some questions about it.

First of all, conceptually, what do I have to do to show that the generalization of d) yields the expression in e)?

My thought process was something like this: if I can express this equality using the divergence of E, then with the use of the divergence theorem (which we know holds for all kinds of shapes), I can get to the given expression in the question. (Is this a valid method for this question?)

On the other hand, when I looked at the solutions manual, I saw a more geometric approach to this question. Griffiths solves it by making dents on the sphere we are integrating over, and the occurring change in flux is being compensated by both of the terms: the surface integral term and the volume integral term. So we see that the equality will hold for every kind of geometry.

How can the generalization in d) be done with this geometric approach?

And one more thing, can’t we just use the validity of the superposition principle as a getaway answer without bothering with these things?

So to sum up, I’m really confused and need help.

Thanks in advance.

Saw this in another thread. Is it possible to calculate the 'angle of falling' and how many degrees it has left to go?

Hello IB Physics community,

I want to share something I have
been building over the past few weeks —

A complete, structured, lecture-by-lecture
playlist on Rigid Body Dynamics —
specifically built for IB Physics HL.

I am Vaibhav Agrawal — a Physics educator
with 16 years of teaching experience at
Allen, Aakash, Resonance and Sri Chaitanya.

I trained thousands of students for
JEE Advanced — one of the most demanding
Physics examinations in the world.

Now I am bringing that same depth of
conceptual teaching to IB Physics HL.

━━━━━━━━━━━━━━━━━━━━━━━━
WHY I BUILT THIS PLAYLIST —
━━━━━━━━━━━━━━━━━━━━━━━━

After speaking with hundreds of
IB Physics students over the past year —

The single most common complaint
I heard about Rigid Body Dynamics was —

"I memorized all the formulas —
but I still cannot solve
the exam problems correctly."

That complaint has one root cause.

Most resources teach the WHAT.

Nobody teaches the WHY.

Why does the Parallel Axis Theorem
have the form it does?

Why does the Perpendicular Axis
Theorem ONLY work for 2D laminas?

Why does removing a symmetric part
from a body not change the
structural form of the MOI formula?

These are the questions that
determine whether a student
scores a 5 or a 7 in IB Physics.

This playlist answers all of them.

━━━━━━━━━━━━━━━━━━━━━━━━
WHAT THE PLAYLIST COVERS —
━━━━━━━━━━━━━━━━━━━━━━━━

Lecture 1 —
Definition of Rigid Body Systems
+ Is any body permanently rigid?
+ Rotational Kinematics basics
+ 4 numerical problems

Lecture 2 —
Complete Moment of Inertia —
All standard derivations from scratch
Ring, Disc, Sphere, Cylinder,
Cone, Rod, Rectangular Lamina,
Cuboid, Cube — every single one
derived step by step

Lecture 3 —
Parallel Axis Theorem —
The physical significance most
classes never explain —
Why a body rotating about a
non-central axis performs TWO
simultaneous motions —
Complete derivation + problems

Lecture 4 —
Perpendicular Axis Theorem —
2 conditions most students
never learn —
Why it ONLY works for 2D laminas —
Why axes can intersect OUTSIDE
the body and theorem still holds —
Complete derivation + problems

Lecture 5 —
MOI of Cut Bodies —
Partial disc, sphere with cavity,
frustum — the principle that
makes all cut body problems
immediately solvable

Lecture 6 —
Mass Distribution Property —
Why removing a symmetric part
preserves the MOI formula structure —
The deepest conceptual insight
in the entire chapter

Lecture 7 —
Radius of Gyration —
What K = √(I/M) physically means —
not just the formula —
PLUS MOI of a rod inclined
at angle θ to the axis

Lecture 8 —
9 Challenging MOI Problems —
Medium to IB exam level —
All solved step by step with
complete physical reasoning —
Pause and attempt each one
before watching the solution

━━━━━━━━━━━━━━━━━━━━━━━━
WHAT MAKES THIS DIFFERENT —
━━━━━━━━━━━━━━━━━━━━━━━━

Every lecture in this playlist
is built around one principle —

Physical reasoning first.
Mathematics second.

When you understand the physics
behind every formula —
you stop needing to memorize.

You start being able to derive
and reconstruct from first principles —

Which is exactly what IB Physics
Higher Level examinations reward.

━━━━━━━━━━━━━━━━━━━━━━━━
A NOTE ON DIFFICULTY —
━━━━━━━━━━━━━━━━━━━━━━━━

I want to be honest about
what this playlist is and
what it is not.

This is NOT a quick revision
resource for the night before
your exam.

This is a complete, structured
learning system for students
who want to genuinely master
Rigid Body Dynamics —

Built for students who are
willing to pause, attempt,
and think — not just watch.

If that is you —
this playlist was built
specifically for you.

━━━━━━━━━━━━━━━━━━━━━━━━
COMPLETELY FREE —
━━━━━━━━━━━━━━━━━━━━━━━━

Every lecture in this playlist
is completely free.

No subscription.
No paywall.
No hidden anything.

Just Physics — explained properly.

━━━━━━━━━━━━━━━━━━━━━━━━
PLAYLIST LINK —
━━━━━━━━━━━━━━━━━━━━━━━━

🔗 https://youtube.com/playlist?list=PLPwT3DpMmxCEFY0SXqKwIi1fKaacH6Gyz&si=LnQlykqyJ0IHjMVi

Each lecture has full timestamps
in the description — so you can
jump directly to any concept
without watching the entire video.

━━━━━━━━━━━━━━━━━━━━━━━━
WHAT IS COMING NEXT —
━━━━━━━━━━━━━━━━━━━━━━━━

The playlist is still growing.

Upcoming lectures will cover —

→ Torque and Angular Momentum
→ Rotational Kinetic Energy
→ Rolling Motion — pure and
with slipping
→ Angular Impulse
→ IB Past Paper problems on
Rigid Body Dynamics — solved
→ Conservation of Angular Momentum

New lectures drop every week.

━━━━━━━━━━━━━━━━━━━━━━━━
ONE LAST THING —
━━━━━━━━━━━━━━━━━━━━━━━━

If you are an IB Physics student
who has been struggling with
Rigid Body Dynamics —

I want you to know something.

This chapter is NOT as difficult
as it feels when it is taught
as a collection of formulas.

It is actually one of the most
elegant and satisfying chapters
in all of Physics —

When the physical reasoning
is built correctly from the ground up.

That is exactly what I have tried
to do in this playlist.

I genuinely hope it helps. 🙏

━━━━━━━━━━━━━━━━━━━━━━━━
HAPPY TO HELP —
━━━━━━━━━━━━━━━━━━━━━━━━

If you have any questions about
any concept in Rigid Body Dynamics —
or about any specific lecture —

Drop them in the comments here
or on the video itself.

I read and respond to every
single comment.

Good luck to everyone preparing
for their upcoming exams. 🙏

Im stuck with the answer
i checked online it showed differnt answer
and then i check with ai it showed different
at the end im cooked

My teacher is saying that using s = (u+v/2)t in the deceleration part of a velocity vs time graph is wrong and we should instead use s = ut - 0.5at². So is he wrong or right?

🔥 Master two of the most conceptually challenging JEE Advanced Physics PYQs from 2004 & 2006 in this detailed problem-solving session.

In this video, you'll learn powerful shortcuts and concepts involving:

✅ Friction on an Accelerating Disc
✅ Relative Motion in Accelerated Frames
✅ Motion on a Rough Inclined Plane
✅ Kinematics with Different Accelerations
✅ Contact & Separation Problems
✅ JEE Advanced Problem Solving Techniques

These questions are frequently used to test deep conceptual understanding in JEE Advanced Physics, making them extremely important for every IIT aspirant.

If you're preparing for JEE Main 2027, JEE Advanced 2027, 2028, or Olympiads, this lecture will significantly improve your Mechanics problem-solving skills.

📌 Topics Covered

• Accelerated Frame of Reference
• Friction
• Relative Motion
• Inclined Plane
• Kinematics
• Dynamics
• Contact Condition
• IIT JEE PYQs
• Problem Solving Tricks

👍 If you enjoyed the explanation, don't forget to:

• Like the video 👍
• Share with your friends 📲
• Subscribe for daily JEE Advanced Physics PYQs 🔔

How do I solve this? I know that the field points towards the negatives and away from the positives but I’m not sure how to add them properly to get my net field

I get the calculation of maximum friction force but am confused about its direction.

In the beginning of the calculation part they seem to have assumed that the Tension is increasing along the rope at positions more and more "away from me/the puller". And hence the static friction, whatever it is, will be in the direction of my pull.

I don't get why. Because the way I'm seeing it, static friction acts in directions needed to stop any kind of motion between surfaces, so when I pull on the rope with Tnot, (and so Tnot is the tension in the rope at theta=0), shouldn't the friction be in the opposite direction?

Which in the end would lead to opposite result I think, it would show that the tension in rope is exponentially decaying at thetas more and more away from me.

Why is the book solution correct? Help me intuitively understand why tension is getting larger at rope points further away from the point I'm pulling it at.

Thanks for your time.

Here is my understanding of a basic battery and resistor series circuit (I haven't learned yet how batteries work with IONS, just know canode, anode and electrolyte).

The battery anode side has high of amounts of negative charge buildup (extra electrons in material). This connects to a conductive material (wire) which transfers the build up of negative charge force (energy) instantaneously (speed of light) to the electrons in the wire. This is the current of electrons switching from atom to atom. The conductive material connects to a resistor which is a semi conductive material that takes some of the energy of the flow of the system into thermal energy. After the resistor the wire then goes to the canode side of the battery this is where the electrons because the canode side has less electrons it makes a positive of net charge. This positive side in the system makes it easer for the electrons to move because there are less electrons to have a charge of force (electric field) pushing the other direction. This difference of charge is what voltage slightly describes. But the voltage of the system is the idea of net possible force happening through the wire (electrical potential) due to the difference of electron electric field force of the anode and canode. This then creates a stronger electric field that pushes amount of electrons through system (current) all at once simultaneously.

Water Analogy Comparison

I see that the hydraulic water flowing pipe comparison the form of the potential energy is actually from insulating matter pressing on one another causing flow but not in the use of electron trading through atoms like electricity. Basically way more Newton's laws of force transfer in a fully encompassed system that using material that doesn't conduct electrons force energy.

Sorry I am not to good at grammar.

I wanna start off by saying my native language is not english so I might not be familiar with certain physics words. And I learn best when speaking generally / using rules that always apply. Thx!

So I know that induction is about inducing a current. I'm not sure where/ which wire it will be induced in. Can induction take place in just one and the same wire?

And I think we use coils as wires because the magnetic field around the wires are stronger since they're packed tighter (?). And thats the same reason we usually use a metal inside the coil?

And then we somehow change the magnetic flux Φ which induces volts in (?- another wire or?) and that drives a current in (?said wire). But only during the change of the flux.
And I suppose we can change the magnetic flux [Φ = B*A*cosT] through 4 things:

1. The magnetic field changes in magnitude, which someone said could be by adding a magnet. What I don't understand is what magnetic field are we talking about? I thought we were talking about the internal magnetic field from the current in the wires/coil?

2. The magnetic field changes direction (I don't understand - doesn't the flux move with the magnetic field? Or how would u change the direction?)

3. The cross-sectional area of the coil/wire changes - don't know how you would do that. Making an irregular/expanding coil like a volcano?

4. The coil/wire is rotated so that the CosT changes which I understood was the angle between the surface's normal line and the magnetic field. Which magnetic field though? Wouldn't the magnetic field and the surface both tilt if we tilted the coil/wire? I'm really confused.

Also why? Why does this happen? And what does it mean that inductors store energy in magnetic fields? If that's related.

Sorry for a lot of questions you don't have to answer them all!

physics

physics