# What is Phyics: Definition and 47 Discussions

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1. ### I enjoy complex problems in science

Male in my twenties, enjoying hard problems in engineering, mathematics, and physics.

3. ### Help please with this dynamics exercise

This is the exercise: Please help me ( question 4 and 5). Here is my effort: First, I represented the forces on both objects. Then, i found F⁰ = 5N (question 1) After that, (question 2) + (question 3) I hope it's even correct.

5. ### B Questions about the Universe: Positive & negative fields and effects

So I saw an article about the universe and lets say the article saied: the essence of the universe, which is impossible, as it has been proven that universal constants such as the gravitational constant and the speed of light indicate the existence of unified physical laws that govern the entire...
6. ### Vector Math Problem (Boat crossing a River)

My answer is 130.54... Is that correct?
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### Understanding how time derivative = acceleration

I'm having a hard time understanding some concepts and would really appreciate some help(not super smart so I need some things basically dumbed down). In my physics lab we're going over Newton's Second Law. There's a statement in the lab papers I don't understand. It states "As you should know...
8. ### Taking the derivative of a function of a function

Summary:: According to Yale’s University PHYS: 200: v*(dv/dt) = d(v^2/2)/dt Could someone explain how has he reached that conclusion? He claims to be some standard derivation rules, but I can’t find anything about it. As much as I can tell: (dv/dt)* v = v’ * v = a* v thanks! [Moderator's...
9. ### Please check my solutions -- Mass being pulled with an angled rope

A block of mass M = 4 kg is pulled by a force F = 100 N forming an angle of 60 degrees with themhorizontal plane with friction coefficient 0.3. Determine the work of force F, friction force and normal force.
10. ### Why a 20 Ohm lightbulb won't light up in a closed circuit?

When using the voltmeter and ammeter to investigate the circuit, it was found that the batter had a current of 0.67 A, the two 30 Ω bulbs had a current of 0.17 A, and the two 10 Ω bulbs had a current of 0.50 A. In terms of voltage, each bulb had a voltage of 5 V. When the switch was closed, the...
11. ### Admissions Phyics REU personal statement critiques?

I just finished my personal statement for physics REU applications, and I was wondering if anyone would be willing to read it and give it some critiques or general advice. If accepted, this will be my first REU. I'm applying to 10 schools. Thanks! *** Physics never actually caught my eye until...
12. ### Worksheet Problem about Power (average power of a car accelerating up a hill)

Homework Statement A 1130 kg car is initially at rest when it accelerates up a 21 m high hill. When it reaches the top of the hill it is traveling at 18 m/s. If it takes 6.5 s to reach the top of the hill, what was the average power of the car? Homework Equations W = Fd P = w/t The Attempt at...
13. ### Accelerator radiation protection program

Hi everyone, I have this question attached from the ABHP exam in part B you are asked to list and justify 4 major elements for accelerator radiation protection program for this specific facility, I have written some answers which are : 1) ALARA which includes : time distance shielding source...
14. ### Engineering Does an astrophysicist (PhD or post-doc) need computer engineering?

Does an astrophysicist in research areas such as cosmic structure and evolution, galactic archaeology, and/or black hole phenomena require extensive skills (i.e. undergraduate degree) in computer systems engineering/computer engineering? The idea is to do a combined degree with computer...
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### A dinner plate, of mass 580 g is pushed .... find work/F

Homework Statement A dinner plate, of mass 580 g is pushed 90.0cm along a dining room table by a constant force of F = 3.60 N directed at angle theta = 24.0 deg below the horizontal. If the coefficient of kinetic friction between the plate and the table's surface is 0.440 determine a. the...
16. ### How to find the wavelength of the sound of the tuning fork?

Homework Statement 1) find the wavelength of the sound of the tuning fork (cm) 2) what's the vertical distance x from the top of the pipe to the antinode above the pipe (cm) 3) find the frequency of the tuning fork (Hz) Homework Equations velocity = wavelength . frequency for pipe closed at...
17. ### Total energy within a specific region.

Homework Statement A cubical region 1.0 m on a side is located between x=0 and x=1 m. The region contains an electric field whose magnitude varies with x but is independent of y and z: E=E0(x/x0), where E0 = 32 kV/m and x0 = 6.0 m . The answer needs to be in μ J. Find the total energy in this...
18. ### Dispersion relation ~ modern phyics (solid state physics)

Homework Statement Which cannot be the structure of two acoustic branches, nor three acoustic branches? Simple cubic, FCC, BCC, diamond cubic, NaCl lattice Homework Equations N/A http://solid.fizica.unibuc.ro/cursuri/solid_en/curs_solid_EN.pdf#page=61...
19. ### Prereqs for learning particle physics?

I want to start studying particle physics on my own and wanted to know what the prerequisite are? I'm in my second year of college and have finished Calc. 3 and Physics with calc. 3. I'd also be interested in textbook recommendations.
20. ### Calculating Wing Lift with a DIY Scale and Air Supply

Hi! I have attached a small sheet of wood to a stand and then all of it to a scale. After that with a air supply I've made wind go through the "wing". Due to lift, the scale showed up a negative value. Knowing that value, is it possible to calculate the lift of the wing? Thank you
21. ### Programs Is a Minor in Mathematics Worthwhile for a Physics Major?

My first 2 years in college I was a little lost in what I wanted to do so I completed almost all of my generation ed classes. I finally realized I love physics, I am interested in astrophysics although I know I have time and opportunities to change my mind . Happily I attend a school with a...
22. ### What is the wavelength of light used in Young's double-slit experiment?

Homework Statement A student performing Young's experiment with a single-colour source finds the distance between the first and the seventh nodal lines to be 6.0 cm. The screen is located 3.0 m from the two slits. The slit separation is 2.2 x 10^2 nanometres. Calculate the wavelength of the...
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### I passed 10th and preparing for IIT. Which books help me to.

I am new here
24. ### Help with questions on becoming a surgeon?

Im almost 16 and in 10th grade and I am very interested in biology/human anatomy. But when i was in 9th grade i was homeschooled and it wasnt for me and i ended up procrastinating to the point were i was kicked out in the middle of the second semester (but you need to finish the whole semester...
25. ### Conservation of Momentum in Explosions

Homework Statement Cart 1 and cart 2 are initially at rest, and after the explosion the momentum of the two carts was the same. If the two carts were moving at some initial speed v0 before the explosion: would the momentum of the two carts still be equal? Homework Equations Momentum. mvi=mvf...
26. ### Geiger counters and activity

I'm doing high school physics and if a question says something like: A radioactive source gives count rate of 110 counts per second Can you say that the ACTIVITY is also 110 bq? My second question is how would a gieger counter detect gamma radiation? It is the least ionising of all three...
27. ### Some advice for a perspective student in phyics?

Hello fellow phyisics geeks, I am quite happy to finally find a forum in which the topic of physics is commonplace. I have am new here posting, but I have been reading posts here for a while. I do have some questions that I would really appreciate some help with. First a little about myself...
28. ### History Experiments and history of phyics

Hi To gain a more intuitive understanding of physics, I want to learn about the experiments that led to the formulations of the theories. What books can you guys recommend?
29. ### Calculus vs. algebra based phyics 2 (electricity and magnetism)

I am a biochemistry major and I need to take the first two introductory physics courses as a prerequisite to physical chemistry. I can take regular pchem, which requires calculus based physics or pchem for biochemists, which only requires the algebra based physics. With the way my university...
30. ### Rearranging Young's Modulus Equation for Force: Help Needed!

Homework Statement Hi all I'm new and wondering if you could help me rearrange this equation for a Young Modulus question: Homework Equations Equation for Young Modulus is E = F*L/A*ΔL * is multiplied / is divide How can I make F the subject of this equation? The Attempt at a...
31. ### Derive that the lagrangian in classical phyics is L=T-V

Hey, can somebody show me how to derive that the lagrangian in classical phyics is L=T-V i have seen this formula so many times, but i have no idea where it really comes from?
32. ### OUNT OF HEAT THAT FLOWS DURING THE EXPANSION

Homework Statement 3 Moles of a monotomatic ideal gas undergo an isothermal (T=50 Degrees Clecius) reversible expansion from a volume of 3m^3 and a pressure P1 to a volume V2 and a pressure P2. The gas does 9.7kJ of work in the expansion. Find: a) the pressure P1 b) The volume V2 c) The...
33. ### Calculate the avg speed phyics help

"Calculate the avg speed" phyics help Homework Statement A caiman swims 190 meters at a speed of 6 m/s. It then enters a stream and slows to 4 m/s for 340 meters. What is the average speed of the crocodile? 10 minutes ago - 4 days left to answer. Homework Equations The Attempt...
34. ### How can I study physics without getting a second undergrad degree?

Hi, I have a problem. I have a bachelors in Geography and I am going for my masters in Geography in the fall. I LOVE this subject so I am planning on finishing it. However, lately I have become more interested in hard science and I want to study physics. How can I accomplish this? I know...
35. ### Computer knowledge for theoretical phyics

Hello! I am going to do bachelors in theoretical physics in next year,so I want to know what kind of computer knowledge needs for theoretical physics (I mean even fast typing programming) Thanks Have a nice day and happy x'mas!
36. ### Courses Help with learning phyics over the course of the year

Hey guys, I'm starting my sophomore year in high school this week and I'm intending to study for the physics olympiad for the next two years but I had a question about how to manage my work load. I already get a lot of work as I go to one of those competitive high schools, but I'm making it my...
37. ### Phyics Circular Motion help.

Homework Statement A 240 g block on a 58.0 cm-long string swings in a circle on a horizontal, frictionless table at 85.0 rpm. A. What is the speed of the block? B. What is the tension in the string? Homework Equations Look at the link in #3. The Attempt at a Solution I'm not...
38. ### I used to be good at phyics, but

I used to be good at phyics, but... That was 1987! I was at the range the other day with some guys when the question of maximum cannon range came up. I knew it had to be 45 degrees but that was all I could remember. Homework Statement A cannon fires a 1kg iron ball at a 45 degree angle...
39. ### What do people think of the Physics department at Hull?

I got an offer to do Physics and nanotechnology from Hull (one of the only 4 places that do the course i want to do) and i wanted to know what people think of the physics department there. I'm not going to get three A's and get into birmingham currently the grades I'm aiming for are BCC in IT...
40. ### Programs Second Degree in Physics: Benefits for EE Career?

Hi everyone, So I am a college junior in Electrical Engineering. After getting my B.S. in Electrical Engineering, I plan on getting a master's degree in Nuclear Engineering. What came to my mind the other day is that I could get a second B.S. in Physics with the addition of the following...
41. ### Grade 11 Physics Project: Build Car to Go Farthest Displacement Under 1m

I have my final Assignment for my Grade 11 Physics Class, We have To Build A car that will Go The " Farthest In Displacement" , it must not be bigger that 1 meter in any measurement. There must be no electronics( motors, nos) but it must be powered by a 1kg weight. Any ideas? I'm...
42. ### AS Phyics Coursework-Sensor Project

Homework Statement Hey guys, firs post here, like to say this seems to be nice forum, very helpful and friendly, hopefully It'll help me for months to come, and I can help as well. Suprised not to see any other topics on this, either that or my searching skills are naff, but down to business...
43. ### How Much Work Does a Crane Do to Lift Soil?

Homework Statement A crane lifts a 2.25x10^3 bucket containing 1.15m^3 of soil (density = 2.00x10^3kg/m^3) to a height of 7.50 m. Calculate the work the crane performs. Homework Equations D=m/V W=Fd The Attempt at a Solution F=2n25x10^3N d=7.50m D=2.00x10^3 kg/m^3 V=1.15m^3...
44. ### Boat Statics, Mastering phyics problem.

Information given: boat owner pulls her boat into the dock shown, where there are six capstans to which to tie the boat. She has three ropes. She can tie the boat from the boat's center (A) to any of the capstans (B through G) along the dotted arrows shown. Suppose the owner has tied...
45. ### Superman Returns Phyics *SPOILER*

OK, I'm giving away the ending, so don't say I didn't warn you...At the end, Superman lifts Luthor's new landmass into space. I did some rough hand calculations to figure out how much energy Superman had to use to lift the island into space. Judging from the scale presented in the movie, I'm...
46. ### Creating a Formula: Force of Gravity at Different Elevations

I really really need help with his.. How can I make a formula that will give me the force of gravity at different elevations? Like.. x would be elevation and the y would be the force of gravity. I know I have to use Newton's law of Univerisal gravitation and sutff, but I don't know where to...
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### Where Can I Find Collisonal Physics Thesis on Atomic Hydrogen Ionization?

Hallo Do u know any Websites where I can download collisional phyics thesis or E-bookin ? Thanks