2. ### Would someone mind checking my proof? Intro Real Analysis

Here is my solution. I used mathjax to type it up in Overleaf. I feel like it makes sense, but I also have a feeling I might have "jumped the gun" with my logic. If it is correct, I would appreciate feedback on how to improve it. Thanks!

Hey everyone! This might be a bit of a dumb question, but I'm not familiar with much in the programming world. I know a few languages that I've learnt on my own (online) or through a course in school (MATLAB). When it comes down to coding outside of matlab or a website, I'm not sure where to...
4. ### Studying Should I start with a basic physics book without calculus?

Hi, I want to start learning physics as I have never studied it in my life but have now taken an interest towards it. I have quite literally zero knowledge on physics, so assume I haven’t taken middle school or high school courses on physics, as I haven’t. I’m 17 currently, but that shouldn’t...
5. ### How to learn physics if I know calculus but zero physics?

Hi, I have decided I like to learn some physics as I know absolutely zero physics and also including chemistry or biology, and I’d like to learn a bit of all 3, to the high school level perhaps. It seems that from, what I’ve read if I want to learn chemistry, I’ll first have to know physics, and...
6. ### The use and meaning of the three beginning physics equations

The first three equations i was given is as follows: Vf = V0 + at Vf^2 = V0^2 + (1/2)at^2 x = V0*t + (1/2)at^2 [why do they sometimes use y instead of x or V0,y?] I don't understand in what situations i would use them in nor do i understand why you us V=gt or X=Vx*T. (i understand g can is...
7. ### Number Theory Cryptanalysis books?

Hey guys, I just bought the book Elementary Cryptanalysis: A Mathematical Approach by Abraham Sinkov, yet before I start it, I would like to know if there are any prerequisites I should know about as I am 16 and I still haven't even taken all of high school mathematics although I am self...
8. ### Which powers works on bead on a string?

Homework Statement I know that a bead is threaded on an metal sring (no T), and the bead is not moving/ The metal string moves in circular motion at a slope of 60 degrees. The string moves one spin in one second/ which powers works on the bead? Homework Equations The Attempt at a Solution
9. ### Studying Am I supposed to understand everything in a formula?

When studying equations, formulas, laws - am I supposed to understand each bit of information ? For example, let's take Fick's law: So I can memorize the law and I can tell with words what is "t", what is "x", what is "D", and so on, but I don't truly understand why is one divided with the...
10. ### B Coefficient of Restitution

Where does the Coefficient of Restitution equation come from, in terms of the Conservation of Energy? The measure of efficiency is the velocity after the collision divided by the velocity before the collision, but how does it get to that point? I'm trying to view this focused on an object that...
11. ### B Work-Energy Theorem and GPE

When using the work-energy theorem (Wnet=ΔE), when do you take gravitational potential energy into account? Change in energy implies all types of energy involved, but in what cases would PEg be a part of it?
12. ### Potential Energy Change

Homework Statement A 95-kg mountain climber hikes up a mountain to an elevation of 5000 m. What is the change in the climber's potential energy? Homework Equations I might be missing something but here's everything that might be relevant: w=fx p=w/t p=f*v KE=1/2mv^2 PEg=mgh PEe=1/2kx^2 Wnet=E...
13. ### B What is the relation of mass and power?

How should power be calculated in a situation where distance and time are both given, as well as mass. At first, I was thinking of just using W=Fx (force as mass x 9.8) to solve for work, and then I would take the solution for work and put it into P=wt. Does this make sense? That's my best...
14. B

### Help for a beginner -- How to learn physics starting from the beginning?

Hi, let me introduce myself. My name is Paolo i’m from Argentina and I have 26 years old. I study “skills in the direction of sales teams” and I’m the coordinator of a sale team. Since I was 15 I love all referd to physics and six years ago I start seeing videos of talks from many scientific...
15. ### Point me in the right direction -- Quantum Physics learning resources

I am trying to learn all about Quantum Physics on my own but I am struggling to find credible sources of information. As you are probably aware the internet is filled with misconceptions, crackpot science and weird stuff about spirituality (at least that's what I find when I try and research...
16. M

### Where to start studying GR?

First of all, I'm new here, so hello everyone! Apologies if this is posted in the wrong thread, I recently started getting into high-ish physics in general, so I'm coming from a low-ish background in the way of math- a couple courses of calculus (single variable covering the basics of the...
17. ### Find the resistivity of the wire: why no internal resistance shown for the source?

I'm having a difficult time understanding why the internal resistance of the EMF source is disregarded in this problem. 1. Homework Statement You are asked to determine the resistance per meter of a long piece of wire. You have a battery, a voltmeter, and an ammeter. You put the leads from the...
18. M

### Intro Physics Why are the Feynman lectures not good for beginners?

Is it because it is more rigorous than books like Halliday and Resnick? Or maybe you need to digest those books as a prerequisite for the feynman lectures? Or maybe people don't believe a regular person could digest the feynman lectures as a introductory level physics book? If someone is a...
19. ### Car on a hill - reasoning for static friction

Problem : A car of mass ##m## is parked on a slope. What does static friction ##\mu_s## have to be for the car not to slide down if the incline of the hill is ##30## degrees? ******* For this problem I have the following forces, where the hill is inclined upwards to the right: Upwards ...

I'm really interested in quantum physics and want to my own learning on it,but what does it contain, generally? And where should I start with it?
21. ### Can someone help me chose a motor for my hand drill?

Background: (I'm a beginner) I plan on using PCV pipe for the main body. The drill's purpose will be to install screws into pre-cut groves (basically a motorized screwdriver). These screws will be only a couple centimeters tall so the motor will only need a moderate amount of torque and rpm. It...
22. ### What does this pascal code do?

Homework Statement A small list of business firms have their own registar number which is between 10000 and 30000. The first 4 digits represent the firm and the fifth digit is the control digit. The number is valid if the sum of all its digits are divisible by 7. Create a program which checks...
23. ### How to understand this code written in Pascal?

Homework Statement I just started learning pascal (school curricuulum) and am finding it quite boring compared to python. After skipping a few lessons i came today and we had this code shown. I know it creates a matrix and then transposes it but am misunderstanding the details of the code and...
24. ### Python Which of these codes do you think is the simplest

Since i don't know how to write code here on forums i will upload a picture and explain whats it about. In the picture there are three codes that define the same procedure of finding the biggest number out of three given. The first code in the picture is defining a procedure called...
25. ### Beginning Sets: Advice on Set Building Notation?

I've started Book of Proof, the first chapter of which is an intro to sets. Q.1 Is there any particular way to approach these kinds of problems, other than using intuition / trial & error? I tend to have some difficulty in working out the best way to express the general term of a sequence, for...
26. ### Classical Further reading after Theoretical Minimum

Hi, I've just finished secondary school and am keen to learn some physics before going on to college. As part of this I've just finished reading 'The Theoretical Minimum' by Leonhard Susskind and George Hrabovsky. The book was a really helpful introduction to classical physics and the maths...
27. ### I would like to know what the dynamic force load is...

Homework Statement I am currently doing an internship and as part of my assignemnt I have to calculate the dynamic load on the bearing of a certain part that is rotating about a fixed point. https://www.physicsforums.com/attachments/chute-png.103400/ [Broken] This is the part that moves ( the...
28. ### Intro Physics Textbook recommendations for someone new to physics?

Here's the issue: I am a junior chemistry major and the time has come for me to take a physics class called "Physics for Scientists". I have never taken a physics class before and I hear from my peers that not only is this particular subject extremely difficult, but so is the ONLY PROFESSOR...
29. ### Calculating entropy change associated with change in temperature

Hi folks, This is a question about how to calculate entropy change when there is a temperature change involved. I got the correct answer to this, but I don't actually understand why it's correct..! Any help is much appreciated. Homework Statement One mole of liquid bromine is heated from 30...
30. ### Using Python to calculate projectile motion with resistance

I'm trying to write a program to calculate the trajectory of a projectile with air resistance. I've made the following function which calculates the position of the particle based on a given launch angle and initial velocity: def traj_fr(angle, v0): #function that computes...