Physics Definition and 985 Threads

Hi I am new to the forum. I am a investor, athlete, and a "field physicist." I got a bachelors in physics and Hopefully soon can get a phD. I like to do basic experiments that demonstrates physics.

I am a junior applied physics major. I am supposed to write my thesis topic proposal but honestly have no idea what to do. I wrote a proposal about using bipolar junction transistors to create a dosimeter but there are already studies on it and honestly, I am not sure about it so I am trying to...

here is what i wish to say. basically i am a 23 year old guy who has wasted a lot of time not finishing any course i started and also occasionally trying to be a musician but also did not fully get into that. There were times since completing high school that I found myself very intersted in...

Hi! I'm in my final year of high school and I need to present to a jury a 5 minute presentation on a physics question. I'm looking for a topic that would combine physics and everyday life , similar to explaining ball movement in a given sport through aerodynamics and movement trajectory. My...

Iris electrode The potential distribution in the vicinity of the iris electrode, denoted by ##V(r,z)## is rotationally symmetric. After some derivations, the author arrives at the following two equations: $$\begin{align} E_z &= - V'_0(z)\\ E_r &= \frac{1}{2}V''_0(z)r, \end{align}$$ where...

Summary:: What calculus books do you recommend? Does Thomas Calculus include all the calculus topics? Hi! I'm a 10th grader and preparing for physics olympiads. I'm planning to learn calculus this summer, i self learned prior required topics before calculus (trigonometry, logarithm etc.) ...

Hi, I am solving heat equation with internal heat sources both numerically and analytically. My graphs are nearly identical but! analytical one have problem at the beginning and at the end for my domain. Many people have used the same technique to solve it analytically and they got good answers...

I am using MPLAB X, everything is working great when I work on examples that require smaller or no preload at all, I do not understand why that is the case, is there a limit to the TMR0L? Hello please help asap, my specific case I have: 4MHz crystal -----> 1 / (4MHz / 4) = 1MHz timer I...

I've collected a few starting points (below) but would love to hear from anyone who has their own account! I know TikTok is super popular so any advice on that, in particular, would be greatly appreciated! Thank you. https://www.iop.org/strategy/limit-less/social-media/good-practice-guide...

I gave a short Maxwell's equation history lesson and included a quick explanation of the connection to Maxwell's predecessors. Just wanted to see if I hit those points right. I don't think I made any physics mistakes, but this was a little more conceptual with some calculus flavor as the student...

Hi, I'm learning physics because I love it and I have many questions I'm struggling to understand the difference between laws of motion and universal gravitation Question 1 : For example : every object applies a force to another object like the Earth is attracted to the sun, so is the monitor...

Once a week, on Thursday mornings, donut holes arrive in my office area of the workplace. Except this morning - when Tuesday became a virtual Thursday. The exception to an otherwise universal constant prompted me to examine the physics of the donut hole more closely:

I recently watched this video by David Tong on computer simulation of quantum fields on lattices, fermionic fields in particular. He said it was impossible to simulate a fermionic field on a lattice so that the action be local, Hermitian and translation-invariant unless extra fermions get...

hello, i struggle with this kind of questions and i don't understand the way of thinking and how to solve this. in the first picture i don't understand why Moments about point Aare a*F1 because there is the 2 P forces that do moments.? in the second problem i can't understand why there are 3...

[FONT=-apple-system] do you think there are biological limits to our capacity to understand physics or mathematics?could it be that in the distant future, no scientific progress could be achieved using the human brain, and we have to depend on superhuman level ai to do the work for us?

I was wondering if there is any such textbook which shows how a real physicist actually goes about developing models and or theories to explain experimental observations. I want to see how it is done in practice. Is there such a book? At a level that an undergraduate can understand. It is great...

Hello All : in the near future i will have few interviews as lab assistance and lab apprenticeship , mainly physics labs , do anyone have a source on lab devices to review before the interviews ? maybe i won't be able to find all my old books or internet links Best Regards Hagop Bulbulian

I'm a graduate student and am interested in learning computational solid-state physics. Ideally, I'd like a textbook which covers solid-state physics and the time-dependent semiconductor Bloch equations from a computational perspective. Does anybody have any suggestions?

Summary:: This is similar to the examples of electrical circuit state space analysis, I have been trying to find the state space equations from the following non linear first order differentials but I keep getting stuck. Any help? A) Started off from non linear equations: $$y' =...

How to represent this system in state space form? where: $$ x' = Ax + Bu \text{ and }y = Cx + Du$$ I am trying to create a state space model based on these equations on simulink, need to find A, B, C and D but like I mentioned, i cannot find the solution when the differentials are not of...

My method is silly but here is my attempt Initially we know that the kinetic energy is k = ##1/2mv^2## and the final kinetic energy at the moment before splitting is equal to ##(k + 3k/16)mv^2_1 = (19k/16)mv^2_1##. Substituting the value k to the second equation gives us ##v_1 =...

I am have some questions that have arisen while reading an old but interesting article by Andreas Albrecht [1] that cites an article by Andrei Linde in the 90s on cosmic inflation [2]...Albrecht's paper is related to his ideas on "clock ambiguity" in which he proposes that the laws of physics...

So for this question I just want to make sure that 1. Bohr model is that F_coulomb = F_centripetal? and then get w(r) is called determind? 2. for (b) calculate the frequency, should I use Rydberg formula or what?

Hi my name is Idan. I plan to study for a physics Bachelor at Israel, my homeland. although is way too early I'd like to proceed towards higher education as well, particularly in the US. The problem is that in Israel there is no physics internships and research projects offered for students at...

The image i provided is a section of microcontroller circuit that i used to interface code in C with the I/O port of the microcontroller, in Proteus. I have realized i was only ever told to learn how to measure the voltage and current across the components, Kirchhoff's rules and all, and...

Hello. I have been accepted into a few Graduate programs in physics. I have narrowed down my choices to two: one in America, UMich, and one in Israel, namely the Weizmann institute. There is an important distinction between the two programs. In America, it is a PhD program, which from what I...

I finished my 1st-year physics, took analysis, linear algebra, mathematical logic, classical mechanics, quantum mechanics(I was exempted from intro phy and took some 3rd-year physics courses) I internal transferred to pure maths. The reason is that the curriculum of the physics programme in our...

Which scenario would exert the most force on the skateboarders feet upon landing on the ground? Scenario 1: Skateboarder rides skateboard 15 mph off of 10ft building roof Scenario 2: Skateboarder falls directly vertical (0 mph) off of 10ft building roof Assumptions: -- no friction -- maximum...

By PDE. The book written by Walter Alexander Strauss perfect described a typical undergraduate PDE course I have in my mind. It should at least include: Laplace equations, waves and diffusions reflection, boundary problems, Fourier series The content of the book I mentioned can also be found...

I have no idea how to go about this. Any help would be appreciated thanks :) Edit: I converted the 1.5 rev/s to rad/s = 9.4 rad/s

*** MENTOR NOTE: This thread was moved from another forum to this forum hence no homework template. Summary:: Trying to find transfer functions to design a block diagram on simulink with a PID controller and transfer functions for a water tank system. ----EDIT--- The variables and parameters...

I derived the formula for t but don't know how it works Δt = p/F I got p = mv = 60*8 = 480kgms-1 Δt = 480/120N = 4s Is that correct?

Hello In his book published in 1830, Sadi Carnot expresses doubts as to the universality of his reasoning on gases. It's on page 89. Is it valid for liquids, solids? And he quotes in the text the freezing of water (increase in volume). What experiments or reflections allowed Rudolf Clausius to...

Hey! I want to study physics and math, and eventually, I would like to get a Bachelor in Physics. I quit university about 5 -ish years ago, an Engineering major...I wasn't a good student and don't really remember anything. A couple of years ago I discovered a big interest in Physics and...

Griffiths "introduction to elementary particles" serves a great introduction as a first course on particle physics for undergraduate students. But what are the possible alternatives of this textbook? Like being more beneficial in the long run, more time-consuming, for aspired students. But it...