Physcis Definition and 207 Threads

What are the ideal conditions in which circuit analysis or analysis of an electrical system is done?I know that the air friction,friction between materials is ignored in ideal systems, such as for ohms law applications.What else is ignored in analysis of ideal electrical systems?

1. The problem statement, all variables, and given/known data A block with an initial speed of 20.0m/s slides up a ramp with an incline angle of 30º. (a) (2 points) Write the position as a function of time for motion up the surface of the ramp. (b) (2 points) Write the velocity as a function...

I'm an engineer who has an amateur interest in physics. I have been reading about Einsteins light clock experiment. I understand the principal that when a light clock on a train etc is moving relative to a standing still observer then the light must travel a longer distance per tick. given that...

Hi, I am really very interested in learning physics and becoming researcher or scientist. But I have few problems like I am not good at maths at all I can remember formulas and constants value. I am not at all interested in electricity and magnetism. I don't really know what am I good at. I...

Homework Statement A uniform, rectangular sheet with sides of lengths a and b has a hole of dimensions a/4 by b/4 punched in it as shown below. Find the centre of mass of the sheet after the hole is made. Homework Equations CM= ∫xdm/∫dm The Attempt at a Solution I'm confused on what to...

Let's assume that it is possible to teleport safely (in one piece, with same body structure) to different galaxy using something as wormhole. Then what would be acceleration that participating in such travel human experience? As I know solar system travels at 230 km/s around the galactic...

Hi Guys, I've been learning electric field, and i want to ask about this question.EF net = EF1 + EF2 my EF1 = 9 x 109 * 4 x 10-8 / (0.6)2 = 1 x 103 (From Q1) EF2 = 9 x 109 * 2 x 10-8 / (0.3)2 = 2 x 103 (From Q2) then EFnet = (2+1) x 103 = 3 x 103 and what i get from key answer is 2.2 x 103...

A refrigerator operates on a Carnot cycle. In this cycles, it absorbs 120 J of energy at a temperature Tc while 300 J of work is done on the gas undergoing the cycle. How much energy is exhausted as heat during this process? The answer is 420 J. I am unsure of where to start for this...

Hello astronomers and physicists! My name is Ahmad. I'm Lebanese studying in Dubai, majoring in aeronautical engineering. I'm usually very curious about everything concerning physics, and not only aeronautics. So expect questions concerning various areas of physics. I'm also sometimes Mr...

I have to make a project for school, so I thought that i can make a static electricity car. I wanted to make a car, and stick/put a material behind the car which creates a charge, and then take another material which creates a charge, and rub it. As it creates static electricity, the cars...

Hello all, I have a problem with a typical style of problem I seem to always struggle with. Just to clear this up, I am studying for my comprehensive exams later this summer. So I am going through past problems to bone up on the last two years of grad school. At which point I came across this...

Hi, Early in my college career I switched around majors pretty often, and it eventually came down to Computer Science and Physics. The first year of each major aligned very well with each other so much so that I was able to knock out the first year of each major in the same year. That summer I...

Homework Statement Determine the wavelength of light being used to create the interference pattern in 3 different ways from the given data. -The angle to the 8th maximum is 1.12° -The distance from the slits to the screen is 302 cm -The distance from the first minimum to the fifth minimum is...

Hi, european here. To some circumstances I can't study physics anymore but I'd like to still get into physics. So currently I'm studying computational science at ETH Zürich. Although we can focus in theoretical physics in our bachelors "thesis", the curriulum differs a lot when compared to...

I don't know much about general relativity, but I'm curious if Zeno somehow foresaw the reallty of the universe many many years before Einstein did(without any rigour ofc, but still the idea holds?). Understanding the Zeno's arrow paradox, stating that an arrow is motionless at a certain moment...

I'm having some confusion about the creation of magnetic field lines. How I understand it so far, is that a magnetic field is basically an electric field viewed from a relative point. I don't have a great understanding so far, as I just started to learn about it, but I've learned that objects...

I am studying electrodynamics, in a few more months I have the qualification exam. The guide text is classical electrodynamics, Jackson. I find that book is higher my current level. I have the math tools, but what book do you recommend to use before the Jackson.

Homework Statement A slender rod is 80.0 cm long and has mass 0.120 kg. A small 0.0200-kg sphere is welded to one end of the rod, and a small 0.0500-kg sphere is welded to the other end. The rod, pivoting about a stationary, frictionless axis at its center, is held horizontal and released from...

I have a question regarding the voltage of two different circuits. In the first circuit there is a 75 volt battery with just one 4 ohm resistor. In a separate second circuit there is a 75 volt battery again, but this time there is a 4 ohm resistor and 9 ohm resistor in series. My question is...

Homework Statement A horizontal beam of laser light of wavelength 474 nm passes through a narrow slit that has width 5.80×10−2 mm . The intensity of the light is measured on a vertical screen that is 2.40 m from the slit. Use the result of part A to estimate the width of the central diffraction...

I have decided that I want to pursue a career in physics and chemistry. It is very important to me that my career helps people. While I know that there are current testing and research being done for cures and treatments to numerous diseases, I don' think that biology is the field for me. Thus I...

I am only aware that the formula has to do with entropy/thermodynamics. I could really use the help on how it applies in physics and what the formula is really about.

Hey, Some time ago I have posted a similar question here about my doubts on my CS course plan. I'm from Brazil, so this should be taken into account, as our university system is pretty messed up. I'm going to graduate this year from CS (need two more disciplines only). I have decided to get to...

Two sinusoidal waves, identical except for phase, travel in the same direction along a string, producing the net wave y(x,t)=(5.5 mm)sin(12.0x -2.0 s-1 * t+0.390 rad), A. with x in meters and t in seconds. What is the wavelength λ of the two waves? B. What is the phase difference between...

Today I was doing some reading and I came across this topic. If we have a stationary hydrogen atom with a single electron in orbit around the nucleus and want to calculate the kinetic energy of the electron we would take the following approach. 1) Using Newton's second law: F = ma ⇒ FE = mac...

Homework Statement What is the change in internal energy (in Joules) of an ideal gas that does 4.675x10^5J of work, while 2.95x10^6J of heat is transferred into the system and 7.95x10^6J of heat is transferred from the system to the environment? Calculate the change in temperature of the two...

Homework Statement The occupation of each single-particle state with wave vector k =/= 0 in the ground state is given by nk = <0|bk†bk|0> where b and b† are bogoliubov transformaition. Find an expression for nk. bk = cosh(θ)ak - sinh(θ) a†-k bk† = cosh(θ)a†k - sinh(θ)a-k Homework EquationsThe...

I suffer from serious bouts of depression/anxiety that come and go for no obvious reason. I started physics this year and its hit me half way through the semester. I made a doc appointment to fix this and I am afraid it will hurt me academically if its not fixed and I won't be able to do awesome...

Homework Statement The river flows 5km/hr in the west direction. The boat that has a speed of 10km/hr. It starts from the south bank to the north. Then the question is to essentially find the angle theta. Homework Equations Tan-1(5/10) or Tan-1(10/5)The Attempt at a Solution Tan^-1(5/10) or...

I know that taking the derivative of certain functions that explain physical phenomena can lead to another statement describing the physical system, the most famous being the derivatives of position. That is, position-->velocity-->acceleration-->jerk-->jounce...and taking any other further...

so for resistance I've gotten r1=6 r2=5 r3=8 and r4=12. then for current i got r1-.30 r2=.24 r3=.06 r4=.06 amd volatge r1=1.8 r2=1.2 r3=.48 r4=.72. I am not sure about my voltage for r3 what i did was Vt-r1-r4 and when i add them up i get 3v so that should be right? and I am also not sure about...

Homework Statement Find the interaction energy ( ##\epsilon_0 \int \vec{E_1}\cdot\vec{E_2}d\tau##) for two point charges, ##q_1## and ##q_2##, a distance ##a## apart. [Hint: put ##q_1## at the origin and ##q_2## on the z axis; use spherical coordinates, and do the ##r## integral first.]Homework...

Hello, I am Awais gul, a student of science subjects and learning the basic of Physics , chemistry and computer science.I have a Question about Newton's third law of Motion. Question : If we Throw a ball on a wall it goes back but if we throw a ball on sand why it does not go back? Newton's...

Is it necessary to have a Physics or Biology degree in order to pursue a Masters in Biophysics ?

I am 29 with a wife and daughter, scheduled to graduate in 1 year with a B.S in physics. My GPA currently sits at a lowly 2.5, however I have been working full time(40 -52 hours a week) while being a full time student. I mostly have received B's in my core classes (2.79 GPA in major). Do...

I see that modern bicycles have curved front wheel forks , how does that affect stability ?

For brittle substances can we say that elastic limit is equal to fracture stress ?

I read the Jupiter is so big that it doesn't really orbit the sun. Is that true?

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/ This is the part that moves ( the brown...

So I am transferring from a community college to the university after this coming semester for a physics degree. Being a transfer student I am expecting to be at a disadvantage when compared to the other students at the school. I have had Calculus based physics 1 and 2 which mainly is focused...

The forces acting on the glider are the gravitational force, the lift force and the drag (air friction). The drag () and lift force () are a function of the angle that the wings have with the gliding direction. =122 with: =0.1+3∙10−32 =122 with: =0.2+0.1− 3∙10−32 In the above equations, is in...

Hi everyone. My name is Shawn and I'm 16 years old. I'll be beginning 12th grade in June. I am a very very big physics lover and I simply adore math. In physics, I am particularly interested in general relativity, quantum mechanics and most of all, superstring theory. I hope to improve my...

Homework Statement A flat capacitor formed by two square plates of side 0.3 m which are 2 mm apart. Source keeps voltage 250 V on the plates. What current flows between the plates and the source if the condenser is immersing in kerosene at velocity of 5 mm / s? The relative permittivity of...

A passenger plane is traveling at a speed of 500 knots, has a mass of 72574.7792 kg, and has an altitude of 35,000 feet. If the pilot lost control of the plane and couldn't reduce speed or anything and the plane was going down at approximately a 40 degree angle, how long would you have until it...

1. The statement, all variables and given/known data Hi I'm doing this experiment where we need to find the wavelength of our laser light source. I am unsure what the variables IV and DV would be and the controlled variables? Also how will I make the graph? I'm in AS level so please don't make...

Homework Statement A 0.02 m x 0.01 x 0.03 block of copper (density = 8.8 g/cm3) is suspended submerged in milk (density = 1.03 g.cm3) by a string. How much tension is in the string? Homework EquationsThe Attempt at a Solution My initial thought for an equation was: T+Fb(buoyancy)-mg=0 T+...

So, my teacher is going to do almost like an interview to the class, asking our knowledge about Dynamics and Kinematics, and I was wondering if I can get questions to test my knowledge in Dynamics and Kinematics to get ready for it.

Homework Statement Consider air expansion inside a cylinder. Assume that the volume and initial pressure is 1 ft^3 and 1500 PSI ABS respectively. If the expansion process is reversible and the path is given by P.V^1.4=constant. Calculate the total work done by the gas to reach the final volume...

In my lectures and notes my professor keeps writing out density as lbs/ft3 and unit weight as lbs/ft3. For a material such as concrete it could have a density of 167 lbs/ft3 but a unit weight of 103 lbs/ft3. I am confused as to how these two values are different even though they have the exact...

Homework Statement A parallel plate capacitor of area 60cm^2 and separation 3mm is charged initially at 90 micro coulomb. If the medium between the plates get slightly conducting and the plate loses charge initially at the rate of 2.5 *10^-8 C per sec then what is the magnetic field between the...