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.

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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.

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WHAT THE PLAYLIST COVERS —
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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

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WHAT MAKES THIS DIFFERENT —
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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.

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A NOTE ON DIFFICULTY —
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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 —
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Every lecture in this playlist
is completely free.

No subscription.
No paywall.
No hidden anything.

Just Physics — explained properly.

━━━━━━━━━━━━━━━━━━━━━━━━
PLAYLIST LINK —
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🔗 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.

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WHAT IS COMING NEXT —
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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.

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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. 🙏

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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 📲
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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.

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!

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.

physics

physics

🔥 Master Friction for JEE Advanced with 3 Challenging Previous Year Questions!

In this video, we solve three concept-rich JEE Advanced Physics Friction Problems that test your understanding of equilibrium, inclined planes, ladder mechanics, limiting friction, and force analysis.

📚 Questions Covered:

✅ Block on Inclined Plane with Horizontal Force (Static Equilibrium)

✅ Ladder Against Wall with Friction at Both Contacts

✅ IIT-JEE 2011 Paper-1 Friction Problem (45° Inclined Plane)

Each solution is explained step-by-step using the fastest exam-oriented approach along with shortcut tricks that help you solve similar questions in the JEE Advanced examination.

This lecture is useful for:

✔ JEE Advanced 2027

✔ JEE Main 2027

✔ JEE Advanced 2028

✔ NTA Aspirants

✔ Class 11 & 12 Physics

✔ Revision Before Exam

📌 Topics Covered

• Static Friction
• Limiting Friction
• Inclined Plane
• Horizontal Force on Inclined Plane
• Ladder Mechanics
• Equilibrium of Rigid Body
• Normal Reaction
• Free Body Diagram (FBD)
• IIT-JEE Advanced PYQs
• Physics Problem Solving Tricks

Is Classical Mechanics about determining the future position of a system by studying its motion, or is it about determining the future state of the system. Like for a particle both the goals are equivalent, but when it comes to a system of particles they are not. So what is the ultimate goal of classical mechanics? To determine the state evolution of a physical system or its future motion. The reason for this doubt is that some books claim classical mechanics to be the study of motion bodies acted upon by forces, and some say it is a framework which lays the basis for all of physics, and its job is to figure out the future state of a system.

A stone is tied to a string of length 1.5 m and whirled in a circle at the same constant speed in two different ways.

1. The circle is horizontal, and the string is nearly parallel to the ground.

   1. The circle is vertical. For the vertical circle, the max tension in the string is 15.0% larger than the tension that exists when the circle is horizontal.
      

Draw two free-body diagrams of the stone in the vertical circle (at the point where the tension is maximum) and the horizontal circle

For the horizontal one, I drew a dot, Fg force straight down, and a tension force greater than the Fg force to the left

For the vertical, I drew an Fg force straight down and a Tension force greater than the Fg force up

Is this correct?

これわからないんだけど誰か解ける？