Physics Definition and 985 Threads

For those who have built those small model rockets, please help me understand a very very simple physics problem that i for some reason do not fully get. Why is it that the motor tube does not have a retention ring on it, to prevent the motor from flying out the nose cone? i know it cant be...

Is it possible, that one physics law is "Everything is in motion?" (since zero doesnt belong to nature)...if so, does that implies that black holes move?

I am curious to know if there are any notable differences in the amount and difficulty of the questions between Fundamentals of Physics Extended 11th Edition and Principles of Physics 11th Edition. Additionally, I would like to know if both textbooks treat the theory in the same manner in terms...

Was wondering if anyone knew of any good resources with programming challenges akin to the website "Project Euler" (about page found here). To be more specific, I'm looking for something consisting of problems centred around physics topics that would require some level of problem solving and...

In the solution below it says 22% goes to 0.0309keV. From the diagram above I interpret 22% goes to 0.1298keV with EC(L)/EC(K)=3.0 and not 4.4. Why is that wrong ? Thanks alot!

I was wondering if anyone knows of any technical pop-sci books about condensed matter physics and/or superconductivity that are at the technical level of something like the "A Very Short Introduction" series or the Feynman lectures. That is, something that goes sufficiently into depth into the...

Is it possible that when you dream, you are actually traveling through different realities, and going into the consciousness in another reality? This seems to explain how our dreams can be similar to what we preceive as our "actual" reality, or drastically different. You can also tie this...

Hello! My research is mainly in atomic and molecular physics but from time to time I come across nice experimental setups, that show promise for my work, from other fields, like chemistry or even high energy physics. I was wondering if there is a more organized way to explore experimental setups...

Hello folks, I am Alex, a guy in his 20s with autism who enjoys science and physics. After a search, I have joined, cos I want to be able to talk with like minded individuals who share the same interest in science as I do. Also, I am currently working on figuring out the inner processes of a...

Scientists recently observed a kilonovae explosion. To their surprise, the explosion is completely spherical. They are saying that this is the cause of unknown physics but I don’t understand why they think unknown physics is causing this. What’s unknown about a perfect spherical explosion? My...

Hi everyone. I thought I would pose the question in the title to those on Physics Forums that are currently working in physics research (either as faculty, postdoctoral fellows, or graduate students). I was thinking of setting up a poll, but the last time I had asked a similar question I...

Hi. I am looking for scientific papers, articles and/or even simulations that investigate how many moons it would be possible for earth to have and maybe modern theories about what these moons can be and look like (i.e what characteristics they have) if they were to exist. I have googled and...

I am going over the diffraction condition section in Kittle's Introduction to Solid State Physics physics and I am having a hard time understanding why the phase difference angle for the incident wave is positive while the phase angle difference for the diffracted wave is negative. Thank you...

Cymatics devices using sand allow us to create shapes with sound. Do you know if those shapes depend on the density and the size of the plate? Thank you

TL;DR Summary: Using vector functions how can I find the minimum average velocity (something greater than 11.86m/s) of a ball if the launch angle is unknown and if I have a point that the object must travel through (11.86, 3.47)? In my assignment, I developed a function for a lob shot...

Okay so I am a little confused as to where I made a mistake. I couldn't figure out how to program Latex into this website but I attached a file with the work I did and an explanation of my thought process along the way.

In physics there is a notation ##\nabla_i U## to refer to the gradient of the scalar function ##U## with respect to the coordinates of the ##i##-th particle, or whatever the case may be. A question asks me to prove that $$\nabla_1U(\mathbf{r}_1- \mathbf{r}_2 )=-\nabla_2U(\mathbf{r}_1-...

So this isn't actually a homework question, it's a question that was on the test I just took and I cannot figure out what I'm doing wrong. I've tried solving it three or four different ways, double checking everything, and I keep getting ##15 + 3\sqrt {15}## or ~26.6, which was not one of the...

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i notice with physics, all the equations are a bunch of scrambled sentences or variables being multiplied together. why the multiplication for everything?

Can I become a biomedical engineer after completing a Bsc in Medical Physics?

I'm currently in my first year of a combined major in Physics and Astronomy. I'm hoping to study theoretical cosmology, and get a PhD in physics. I've been told it would be wise to get a double major in Physics and Math if I wish to study theory, but would it also be wise to get a combined major...

Hi. I wrote a little algorithm that calculates some physics equations for education purposes and it's in C++. I'd like to make it avaiable by creating a website and put that code in it so it either interprets the C++ code or preferrably works with an executable (but then how would it be...

Hi, I was watching a documentary on car crashes and how designs are continually being optimised to keep passengers safe. They were saying how many ‘g’s’ certain crashes were based on crumple zones, seatbelt stretch etc. I was interested to do some number crunching to see how big the...

I’m writing a presentation for younger students explaining how science can help them satiate their curiosity in a fun way. This presentation’s goal is to apply as much science as possible to a ridiculous question in hopes of promoting STEM fields. My example is, how many capybaras --the world’s...

I am attending University of Waterloo and my school will allow me to graduate as a Mathematical Physics major without taking any labs/experiment courses (in my school lab is not integrated to physics courses, they are separate courses with separate credits). This could be great because : -...

I'm a 17 years old student and I can't choose between studying Physics or Engineering at university, any advice?

TL;DR Summary: I want to mainly figure out where in the problem solving I went wrong. I understand the correct answer (since I looked it up), but to me, it does not make any sense. I am honestly stumped at this point. Online solutions say that my equation y = 0.5774x-0.003354x^2 should...

TL;DR Summary: Theoretical astrophysics research status in ISRO, India I am from India and want to be an astrophysicist serving my nation. Whenever I check about any ISRO news, it is always about some engineering achievements, like the launch vehicle and never about pure theoretical research...

Hi all, I've been pondering over this question for a long time. Of course physicists are specialists in a specific branch (even in those branches, sometimes they specialize themselves in an ultra-specific sub-branch) in which they produce research. I've noticed some professors at my uni...

Listen just 1 minute, what does it mean when he said nobody understand quantum mechanics? This sound like comedy

I think Atomic physics gets into specific examples and experiments but I think I’m probably wrong. So, I have to ask, what is atomic physics and how is it different than quantum physics?

I know that I need to satisfy the core requirements for a Bachelor's in physics and I have the ability and desire to do it. I live in California.. Here, and I believe almost everywhere, public universities do not allowe enrollment in a second Bachelor's, even online. Private universities are...

im a first year physics student near half way through the year and I still cant get to grips with what how im supposed to study. I try to rewrite my lecture notes using the textbook as the lectures seem to miss out a fair bit of information (and we were told to do this), but this takes me so...

I brought time over to the other side and multiplied to get 686 m/s but that wasn't correct

Hello everyone. I have question about studying of quantum mechanics. My university program isn't good and universities lectures can't help me and I situation next that I should study physics use alone and use materials from internet. I tried do that but I understand that my level of math isn't...

hi, is it possible after a bachelor's degree in architecture to pursue a master's degree in physics and how?

They've gone through calculus (Essential Calculus by Stewart) but haven't had a formal physics class yet (but a lot of pop-physics reading). I recommended Thinking Physics followed by Conceptual Physics by Hewitt, followed by a meaty calc-based book like Krane or YF, but I wonder if an easy...

Hi everyone, I was looking to develop my physical insight when I encountered this book by Lewis Caroll Epstein. For the crosswind problem, I couldn't understand the author's explanation; in particular, his concept of "artificial wind," and the force being larger in this case than the previous...

Hello, I am simulating the process of NMOS construction. as you know, in order to make the LDD, we need two implantations, one before creating oxide spacer and another after creating oxide spacer. at the last implantation, I am facing an error which is shown in the following image: I put...

I know this might be a stupid question, but I am serious. Some of my friends are in graduate programs not much related to their major (a number of my friends majored in math but are in computer science grad programs, and vice versa), so I am curious whether the same holds for physics. In my...

First of all i tried to follow the textbook. Here they start of by modelling the atom as an harmonic oscilator: Then they find the solution as: They neglect the second term as omega_0 >> gamma which also makes good sense so they end up with: So far so good. After this they state the...

I'm watching a nice video that tries to explain how linear algebra enters the picture in quantum physics. A quick summary: Classical physics requires that physical quantities are single-valued and vary smoothly as they evolve in time. So a natural way to model classical physical quantities is...

In the short story "Neutron Star" by Larry Niven, the narrator, Beowulf Shaeffer, is piloting a spaceship on a hyperbolic orbit that is supposed to make a close approach to a neutron star. He says at one point that he sees incoming light from distant stars blueshifted in all directions, and...

One image is attached is the question and the other is my attempt. I believe the pillars would have a downward force of 11760N applied to each pillar since they are spaced an equal distance apart. Now the tricky bit is when Torque comes into play. I believe I need to find the distance the car...

A self-balancing electric unicycle consists of a frame+pedals that the rider stands on, a motor where the stator is attached to the frame+pedals, and a rotor which is attached to the wheel+tire. An EUC is similar to an inverted pendulum: the EUC frame is free to rotate about its axis, limited...

This is part 2 of my thread Collection of Free Online Math Books and Lecture Notes Here, we will consider physics and mathematical methods for physics resources. Now, this is a work in progress. Please feel free comment regarding items you want to be included, or if a link is broken etc. Note...

Hey everyone, A quick question that I hope all can participate: In your educated opinion, what is the biggest question or the biggest problem to be solved in quantum mechanics for 2023? Warm regards, Thiago Munhoz da Nóbrega

TL;DR Summary: Physics book recommendation Hi everyone, I just found this site and I'm thankful for that. I want to study Physics as a pure science but in my city there is no bachelors degree, so I want to study by myself if it's possible. I just don't know where to start or what books should...

TL;DR Summary: Seeking good simulations to build my intuition Hi everyone, I am currently teaching myself classical mechanics, and am 3/4 of the way through "Vibrations and Waves," a textbook from 1971 which was used in the MIT course. It's going okay - I feel like I have a decent grasp of...