Physics Definition and 987 Threads

To estimate the concentration of fog droplets in the air, I thought of the mass of water in a given volume of air: I searched this value on the net, and I found that it is typically around ##0.05 g/m^3##. The mass of a single fog droplet can be calculated from its diameter and density. Assuming...

I'm pretty sure I understand why q^i u^j + u^i q^i is the stress component (i \neq j) of the Heat Flux Stress/Energy Tensor but I can't think of, or find any explanation for why q^i u^i + u^i q^i = 0. I found one reference in Lightman, Press, Price and Teukolsky - Problem Book in Relativity...

[Can skip everything blue] I have made a few threads in the past trying to get an informed perspective on whether sticking with Physics would be the best thing for me. Although, some of you have made very helpful comments, I am not sure if leaving Physics would be right path for me. I realize I...

During the night, I was traveling by local bus. And as I viewed through the window, the light from the street lights and the headlights of other vehicles appeared curved, as shown in the images below: One common answer is: because of refraction Is there any more explanation for this behavior?

This is going to be long, but I request you to read it completely. I finished my Bachelor's 1.5 years ago and it in 2022, I started studying, but I have been having issues with my family and I had to work part time while I was doing this. I had to care for my ailing grandparents and I many...

Hello Everyone, I am thrilled to join this esteemed Physics Forum, a space where the wonders of the universe are explored and discussed with fervor. Allow me to introduce myself as a dedicated aficionado of all things physics, driven by an insatiable curiosity to delve into the depths of this...

Torque_left = 100 kg * 1 m = 100 kg·m Torque_right = 200 kg * (13 - x) m = 200(13 - x) kg·m 100 kg·m = 200(13 - x) kg·m 100 = 200(13 - x) x = 12.5 meters pivot = 12.5 m

How the physics and science limit our cosmos observation and link it to speed of light? I could not find any equation, study or science that can support and limit our observation parameters.

The container and water inside it are at rest. ##F_{net,y}=ma_y## ##N - (m_{container}+m_{water})g = 0 ## ##N = (m_{container}+m_{water})g## ##m_{container}+m_{water}=700g## ##m_{container}+\rho_{water} V=700g## ##m_{container}+0.8(10*10*8)=700g## ##m_{container}=60g=0.06kg## Now we put a ball...

Hello! I can do this task just using this formula s=u*t+a*t^2/2. But just saw an example where someone used this Galileo toerem. Here is task: "An observer stands on the platform at the front edge of the first bogie of a stationary train. The train starts moving with uniform acceleration and...

Hi Folks. I've been retired for a decade. Waaaaay back in time (1980) I got an engineering degree; in other words, in the mid-70s I took three freshman physics courses: Laws of Motion; Electromagnetics; Relativity/Quantum Mechanics. I doubt that I remember anything at all from these classes...

I've seen this question in a textbook Calculate the following commutator [[AB,iℏ], A] I'm not to sure how you go about it i know [A,B] = AB-BA

In 1994 Frank J. Tipler wrote a book titled: "The Physics of Immortality" which appeared to suggest that physics and religion could be united. Absent religious or anti-religious prisms, if the universe were found to be closed (I know, it's not), is Tipler's physics worthy of serious consideration?

HI, I need help wtih my physics work and dont know where to ask

Hi all! Im gonna try to keep it short but as detailed as possible. First of all, sorry for my lower level english, possible misunderstandings of the physics Im talking about and misusage of the forum, Im not sure if vague threads like this is allowed at all. Please feel free to just answer...

I want YouTube channels that systematically raise my mathematics and physics level

Heyy Guys, I am Rohit Nair, SYBSC physics maths student from st. Xavier's College, Mumbai, India. I have a strong curiosity and thirst to learn and solve maths and physics problems. Currently working under a project on pulsars in TIFR, India's research institute. Also, I am into experimental...

This problem is a reformulation and solution of a problem posted earlier that did not go very far. A streamlined solution is posted here for future reference. Solution Shown below are two FBDs for the two paths. From the top FBD, ##N+mg\cos\theta=m\omega^2 R\implies N=m\omega^2...

Hello, you can call me V! I just got into highschool and am interested in physics, but I am super bad at math and science... I've been an english and art person my whole life so it's been tough LOL. I joined in the hopes that surrounding myself with STEM related stuff will have a positive...

I was here over 10yrs ago, at the time, I use LaTex. You still using that today or there's something new? I am encouraging my grand daughter to come to this forum as she's going to college soon. I don't want to tell her to learn the wrong thing as it's been over 10yrs already. Thanks Alan

Hello, I am Aiswarya Lakshmi S, from India. Currently, I am pursuing Masters in Physics. I am very much interested in exploring this subject. Looking forward for a great experience!

Hi all, Hope we have some electron beam evaporation specialists in the house. I'm working with an Telemark Electron Beam Source (Linear Multi-pocket and would like some help with the issues I am facing currently. I'm seeing blue light around both sides of the crucible when the e-beam is turned...

Hello I'd like to write my matura project on a topic of physics. But I can't really find a topic. I think I'd like to do something in the field of mechanics with reference to everyday life. The project requires an input of myself in this work, that means, i have to do something empirical and...

I do not understand enough.

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I am curious to understand how the universe works. I love to imagine if I were the universe or a particle why would I behave the way it does. It's a fun exercise. I am currently preparing for IIT JAM exam. I am glad to be part of this community. I am looking forward to getting to know you...

So excited to learn more about physics and to further my understanding! :partytime: This seems like a nice little corner of the internet. :]

Numerous curiosities that all have answers hidden in physics.

For starters, Im just an average student who just so happens to take an interest in physics. Yet this does not stop me from trying to gain more conceptual clarity on it. As a student, I feel I lack on explaining learnt concepts and discussing it. I believe this forum will help me overcome this...

PADME previous papers arXiv:2305.08684 (hep-ex) [Submitted on 15 May 2023] Status and Prospects of PADME Comments: 6 pages, 12 figures, proceedings from Moriond EW 2023 Subjects: High Energy Physics - Experiment (hep-ex)...

TL;DR Summary: Some universities offer online MSc and phd in physics,are they wirth it? I am what you would describe as wannabe physicist, i like the topic and want to study it but in my country there are no reputable universities that teach the topic in advanced lvls. So can i study it online...

I've noticed lots of physics professors reply before you finish talking. Not specifically talking about questions in a lecture etc, I mean more generally. Not sure how common it is in other disciplines or why, but generally they don't tend to let you finish. As a result often when someone has a...

Set up the force equations: (1) ##mgsin(\beta) - T = ma_{1}## (2) ##TR = I_{s}\alpha_{1}## Multiply (1) by ##R## and isolate ##TR##: ##R(mgsin(\beta) - T) = R(ma_{1})## ##mRgsin(\beta) - TR = mRa_{1}## ##TR = mRgsin(\beta) - mRa_{1}## Plug ##TR## into (2): ##TR = I_{s}\alpha_{1}##...

https://www.nobelprize.org/prizes/physics/2023/summary/

Hee, I believe I have to introduce myself here?😂 So my name is Kate (short for my real name haha). I’m still a teen and interested in physics. I’d like a mentor or something but idk where to get one 😂😂 Well, that’s all for now, Kate

m * g * h + (1/2) * m * v² = m * g * y Simplifying the equation: g * h + (1/2) * v² = g * y Substituting the values: g * 0.614 + (1/2) * v² = g * 2.73 * sin(26.7°) Now, let's solve for v: (1/2) * v² = g * 2.73 * sin(26.7°) - g * 0.614 v² = 2 * (g * 2.73 * sin(26.7°) - g * 0.614) v = √(2...

I received my degree some years ago. Been very focused on optics, astronomy, programming.

My attempt is: Archimedes' thrust on the balloon minus the weight of the air inside it is F=(\rho-\rho_{\rm in})Vg, where \rho_{in} is the density of the hot air inside. Now we have, in general, \rho=\mu {n \over V}=\mu {P \over RT} from the perfect gas law (\mu would be the molar mass of the...

The question : A car and a truck are both traveling with a constant speed of 20 m/s. The car is 10 m behind the truck. The truck driver suddenly applies his brakes, causing the truck to slow to a stop at the constant rate of 2 m/s2. Two seconds later, the driver of the car applies their brakes...

Interested in race car physics whether it be asphalt or dirt CT and chassis set up and all things racing .

hii guys I am studen of physics in high school of Seattle.

Hello, I am new to this website and just don't get everything yet (like attempt to a solution). I'm in the third grade of highschool and this is my first year of having physics as a apart subject.

Consider a pendulum swinging at the North Pole in an inertial frame of reference xyz with the x and y axes in the plane tangent to the pole and the suspension placed at elevation z = l. There is no induction \mathbf{B} and in the chosen system the plane of oscillation xz of the pendulum is...

So I started by just figuring out what forces are going to have torque. I know the one heading straight down from the pivot won’t have any and the one going at an angle from the pivot won’t be included in the net torque since it’s at the pivot. The rest of the forces have torque and they are...

So after Newtonian mechanics and electricity/magnetism, what do physics majors study? Also, is there a textbook you can reference me to that applies to that?

I realize of course that this will probably not apply to all physicists, but at least every physicist in my university's math department is very unrigorous when it comes to mathematics. This is frustrating because some of the physics material seems genuinely interesting, but the lack of an...

Hi, I graduated with an undergraduate degree in physics 16 years ago, and I would like to go back and relearn all that great knowledge that I forgot. I was thinking of the following series of books. -Do you recommend changing the order in which I go through them? -Do you recommend adding a...

Basically this is the Exercise In Fundamentals of Photonics book. We also need to use these two equation (1) and (2) As we all know, in order to make the z' as far as possible, we must place 2 lens with this distance I already figure that thank to the initial condition of the first lens...

Help me solve... I'm getting errors here..