# physics

1. ### Leidenfrost effect and volume of water

I conducted an experiment at school where I changed the volume of water and looked at the time taken for the water to fully evaporate, whilst undergoing the Leidenfrost effect. I'm trying to write up the theory behind it, but I keep getting confused with the terms. There seems to be so many...
2. ### Use Norton's Theorem to solve for the voltage across R5?

Q. Use Norton's theorem to figure out the voltage @ R5. I can't figure this out. Apparently we need to use KVL at a particular node to find voltage at r5 and go from there. But I can't make sense of it. The answer is 17.84V
3. ### Physics Depth Study Advanced Mechanics

Hi, I just got my first year 12 assignment which is a depth study of advanced mechanics. I had one idea of investigating the motion of rockets and satellites. I could even do something with circular motion or projectile motion, taking air resistance into consideration. I just don't what to do or...

Use non-degenerate perturbation theory to solve the following problem: Consider a string of length L, that is perturbed by having its density be slightly higher between x=L/4 and x=L/2. You should assume the density increase is uniform along the stretch. How do the wave vectors change? How...
5. ### How to solve this question

A football player kicks for a field goal 30.91m from the posts. The ball is kicked with a speed of 18.6 m/s at an angle of 45 degrees above horizontal a) how long will it take the ball reaches the posts b) how high will it be when it goes through the posts c) What is the magnitude of the...
6. ### Common Misconceptions in Physics III

Let's get a fresh start here. This is a place to discuss various subtleties in Physics that may be common or generally accepted but turn out to be wrong. -Dan
7. ### Best resource for introductory physics

Hello, my college background is in mathematics, with some physics. I will be working with someone who will be learning college level physics in about 6 months. I would like to help them get a head start. I am looking for a source either a work book or training video which could introduce someone...
8. ### Help with basic Physics work

Hello there :) I'm new to these forums but I suspect they will be very helpful for years to come! I'm trying to study ahead and get a feel for first year of Physics, so I decided to go to MIT's OCW and start going through the course. I came upon one of these worked problems, but the video...
9. ### physics of rear-mounted bicycle carriers

I have what is probably a simple question to most of you as I have had no luck getting this information from the manufacturer or elsewhere on the web... I want to buy a particular bike carrier that sits on a tow bar/hitch and projects rearward from there. The carrier/rack can support 4 bikes...
10. ### physics vs forest

The local dark force (江门地方黑恶势力钟永康集团) alway try every means to supress, isolate, seal off, disrupt and disturb me. They call that "the forest rule". I have no ability to deny their rule in the local place. I feel I die hard. Actually, most of my time is spent on worrying (about the perspective...

https://drive.google.com/file/d/1ybzqPWMJfTolL5VexgkKDHcqWMfd3k7u/view?usp=sharing Hey so I'm kinda really lost in class because my teacher is really confusing. He gave us these three problems for practice for the exam (these aren't assignments or anything). I'd really appreciate someone...
12. ### I would like to know if this is physics?

Hello, I'm kinda stuck on a closed system. My understanding is a repeating instance of equal differences. But to get to that point I thought something along these lines. Well I can't explain totally it came from mainly a graphical nature with scientific models in it. But I'll explain a...
13. ### Physics Resource Sharing Useful Sites, Weblogs, Medias about Physics

Hi, Everyone, I'm new here Let's Share with others what Resources we use in internet 1- arXiv.org (Article) 2- t.me/PhysicsDirectory (Telegram Channel) (For Ebooks)
14. ### Help, Im new to physics

I just started to teach myself physics online, i dont really know where to start. I have this question though, help would be appreciated! :) A biker moves 7.5m/s, when he reaches a downhill he starts to accelerate with 2.3m/s2 A) How long does it take until the biker reaches 55 km/h? B)How...
15. ### Hi, I'm new to Physics. Will a Faraday cage help me?

Hi, I'm new to Physics. I don't have any educational background in Physics. What is a Faraday cage? What does it do? Will it protect one against artificial telepathy? Are there technologies which allows one to force people to think what they want? Will a Faraday cage protect one against...
16. ### IIT physics

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17. ### Math for balance physics formula

No start as time means it. When every unit is 1 as balance, 1m/(sec^2)=1*a. 1m/sec=1*a*t, (1*v=1*a*t). (1/2)*a*(sec^2)=s. (a*t)*t=2*s. t=2*s. 1*s=1*v*t. 2*s=2*v*t, 2*v*t=2*s. 1=1. It is for balance formula 1+1=2.
18. ### Quantum Physics - Eisberg

Why is it that even for incident radiation that is monochromatic, photoelectrons are emitted with a spread of velocities?
19. ### Physics

1.How does the time of flight depend on the angle of elevation at projectile motion? Derive this formula, explain all the quantities and draw a picture to your answer. 2.What are the differences between mass and weight? Illustrate your answer with a picture and give examples...
20. ### Medical physics - Correcting presbyopia

Hi all, I have another problem, this time involving the lens equation. (1/f= 1/v+ 1/u) v and u are in Meters and 1/f is the power in diopters (D) I have solved some problems where the near point of an eye is correct and the far point needs correcting and where the far point is correct...