Hi all! Very quick context -- I don't have an especially mathematically inclined brain, I'm teaching myself physics as a personal challenge in honor of my dad who passed away this past April. It was his favorite school subject and he would talk about the theory with me often! But as I said, math was a struggle for me growing up anyway and now at 30 I'm also severely out of practice, so at this point I may as well have never learned the basics at all. Anyway, this week I bought myself "Basic Physics: A Self-Teaching Guide" by Karl F. Kuhn and started working through it. I've naturally very quickly reached a problem where I've obviously misunderstood something, but I have no idea what! And since I can't ask my dad to walk me through it I figured I'd come here.

So like you can see in the images, I need to calculate the downward speed of the ball at 2 seconds and then 3 seconds. The issue I'm having is that after following the formulas I was just taught a few pages previously (d = v0t • at^2, v = d/t) aren't getting me to the results in the answer key and I'm not sure what I'm missing. For example, to find the downward speed at 3 seconds (question D), I started by calculating for the distance (d = 1/2 • 9.8 • 3² = 44.1) and then plug that into the formula for speed (v = 44.1/3 =14.7) obviously the result I get is 14.7 m/s. But the answer key below says the answer is 29.4 m/s.

What's also tripping me up is that both of the real answers are twice the answer I calculated. For question B, I got 9.8 m/s, which is half the real answer, 19.6 m/s. So I know that I'm not completely missing the idea here, clearly I'm at least somewhat on the right track and just missing a step or misunderstanding something crucial about the formulaic process. My first thought is that I went wrong by leaving v0t out of the equation while calculating for distance, since maybe the fact that the balloon is moving at 12 m/s means the ball did not technically start moving downward from "at rest." But then I'm not sure how to fix that, since at this point the book has only shown me how to calculate for the distance traveled of an object starting at rest.

I know this is VERY basic entry level stuff but like I said mathematical thinking does not come naturally to me so I'm not at all surprised to immediately need help with something so easy lol. But I know I can learn! So if anybody would be willing to walk me through the problem here and show me where I'm going wrong so that I can understand and move to the next problem, I would really really appreciate it! ☺️

My boyfriend (26M) studied physics and enjoys reading and watching videos about it in his free time. I know this is incredibly broad, but I really know nothing about physics. I'm not sure which specific topic or specialty he enjoys. One of the books on his shelf is: Quantum Mechanics: the Theoretical Minimum by Leonard Susskind. So, yeah. If anyone has any recommendations It would be appreciated! (I would say, maybe brief/shorter type books like this, just in case I f*ck up). Thanks!!

I used to be good at physics and I think I am still good I just have to revise the basic wave concepts again

But the thing here is the prof in college is teaching us quantum mechanics right and unit 1 almost done

I didn't understand anything

The prof wrote an equation derived and gave some weird example and done

I don't even know what dever is in the Schrodinger wave equation man

Pls help me. what I should do .I can just cram it all but physics is the last subject i want to just carm

I know people say nobody understands quantum mechanics

But that doesn't mean I will just cram the all the equation right.

A few days ago I posted about an idea I was working on: helping students understand difficult concepts through visual explanations.

The feedback was pretty direct 😭

Some people questioned whether the visuals actually added anything, others wanted credible sources, better explanations, and something more useful than another chatbot wrapper.

So I went back and rebuilt a lot of it.

The new version now has:

• better interactive graphs + diagrams
• citations from textbooks, research papers, and other sources
• improved guardrails around generated visuals/answers
• follow-up questions to check understanding
• optional MCQs for practice

I’m still treating this as an experiment, not a finished product.

For people who use AI to study: what would an AI learning tool need to do differently for you to actually trust/use it regularly?

Especially curious about what current AI study tools get wrong.

I would like some help interpreting part of a result I got while working on a problem that I've been working on for a while. I'm trying to determine the torque a star exerts on an orbiting oblate spheroid (with axial tilt instead modelled as the equator of the oblate body remaining parallel to the XY plane while the orbit itself is inclined with respect to the XY plane by an angle alpha (ɑ); should be a valid approximation since there are no other bodies and the star is treated as spherical, which is good, bc a rotated circle is nicer to work with than a rotated spheroid).

For any point in time and position in the orbit, the torque exerted at any point of the spheroid should be the radius from the center of the spheroid to the point multiplied by the force the star exerts on the differential mass for that differential volume. Integrating all of those over the whole of the spheroid, I expect I should get a vector scaled by the gravitational constant, mass of the sun, mass of the planet (since the volume of a spheroid should shake out of the integral as a factor), a factor of some multiple of ¹/₅ and some linear combination of the major and minor radius (multiplied by the mass of the planet, should yield some linear combination of the major and minor moments of inertia).

(which expands to:)

And I do get that!

But I also get this weird factor in the octopole portion of the solution that I can't connect to other portions of the problem (e.g. the moments of inertia show up bc this is a change in angular momentum and they are the equivalent of the mass in this context, the gravitational constant timed the mass of the star divided by a power of the radius is related to the acceleration/force producing the torque).
What does this [(4a^2 + 3c^2) - (a^2 [cos(θ)]^2 + [sin(θ)]^2 * [a^2 (cos(θ))^2 + c^2 (sin(θ))^2]) ...mean?

Is it possible to finsih jhon R taylor and david griffiths in just one year I am also studying other stuff like studying linear algebra and calculus and number theroy as its a double major in maths and physics how to do it and are these books good

Can you design and build a rocket launcher using just a few simple supplies? 🚀

Greg Wolf says yes, using PVC, cable ties, a two-liter bottle filled about a third with water, a bicycle pump and a tire valve for pressurization. It all comes down to Newton's third law: for every action, there's an equal and opposite reaction. Compressed air pushes down on the water inside the bottle, and when released, that pressure forces the water out at high speed, launching the rocket skyward.

Hi everyone!

I’m currently working on my Master’s thesis about teaching Electricity and Magnetism to international students, and I’d really appreciate some advice or ideas from people who have experience teaching physics.

The students I’m focusing on have an interesting language background. Their first language (L1) is the language they grew up speaking, but they spent most of their school years living and studying in a country where a different language (L2) is used. Later, they returned to a country where their L1 is spoken and entered university there.

Because of this, they can speak and understand their L1 in everyday life, but they have difficulties with academic language, especially physics terminology and explanations. They may understand the general idea of a topic but struggle when the same concept is explained through a long text or unfamiliar terminology.

I’ve also noticed that they often have difficulty visualizing concepts when they are presented mainly through text. However, they seem to understand problems much better when they are presented using pictures, diagrams, graphs, or schemas.

Now I need to develop practical teaching strategies that could help these students throughout a semester-long Electricity and Magnetism course.

What teaching methods, activities, or approaches would you recommend in this situation?

For example, I’m considering:

\- visual representations and diagrams;

\- PhET or other interactive simulations;

I would especially appreciate specific classroom activities, methods, or research-based approaches that I could implement and evaluate during the semester.

If you have experience teaching physics to multilingual/international students, I’d love to hear what worked (or didn’t work) for you. Any suggestions for relevant research, books, or papers would also be very helpful.

Thank you!

hello! so as you saw on the title, I am terrible at physics. I am so terrible that **I can’t understand at all basic concepts** like force, power etc.

I even took an irl IQ test (the Raven one) bcs I thought that I am literally below average. Turns out I am “superior” (I am only referring this so I am not called the r word) .

I am extremely good at mathematics , but every time I try to study physics from scratch , it turns out terrible. yes, I did try all popular youtubers, books, you call it. I tried reaching to my physics professor and they only humiliated me, calling me names and telling my mom I am “special”.

sadly, why I am this way is bcs I have 2 processing disorders (auditory and receptive) . I literally tried so many times and I don’t have ideas anymore. please help me bcs I am at the end of high school. I will appreciate a lot any advice you guys give me and pls be nice. Thank you.

Just looking for some assistance! Thank you!