What is Physic: Definition and 221 Discussions

1. The problem statement, all variables and given/known A karate expert breaks a pine board, 2.2 cm thick, with a hand chop. Strobe photography shows that his hand, whose mass may be taken as 580 g, strikes the top of the board with a speed of 9.5 m/s and comes to rest 2.8 cm below this...

[Mentors' note: No template because this thread was moved from the General Physics forum] Ok so first of all believe me i would not make a new post if i found the answer anywhere online but i i couldn't find it. Right now i am doing an experiment to find the frequency of a bouncing ping-pong...

Homework Statement Homework EquationsThe Attempt at a Solution

So I know if you move a charge in a magnetic field it induces voltage and hence a flow of charge is created which is current. ( Please correct me if I'm wrong). But that's pretty basic right. However, I'm having trouble understanding the use of split rings in the functioning of a motor. I would...

I am currently in 9th grade and have been into astronomy and basic physics for a few years now. I'm thinking about (once enrolled obviously) majoring in physics. Only problems are: 1: Pretty good at math but struggle a bit and end up forgetting a lot of information (at least in algebra) and I...

Homework Statement I have attached the problem. I will write it out: A waitress attempts to push a glass of water of heigh 15.o cm and diameter of 7.00 cm on a dining table, as shown in the figure. If the coefficient of static friction between the glass and the table's surface is 0.350, what...

I understand that condensation occurs when water (in gas form) looses energy and becomes liquid. What I don't understand why some surface is needed to form a liquid water

Homework Statement Three capacitors are connected in series, C1 = 4.5 mF, C2 = 7.5 mF, and C3 = 10 mF, and connected to a 150V d.c. supply. Calculate: (a) the total capacitance...

Could a particle move through and displace a Bose-Einstein condensate, causing it to wave?

Homework Statement In the following diagram a massless pulley is pulled by a constant force of magnitude P. There is no friction between the block and the floor. The acceleration produced in the block if mass m is? PIC ATTACHED Homework Equations Took a1/2=a2 where a1 is accn of block and a2...

Homework Statement here is my problem : Homework Equations like usual, the problem is related with RLC circuits and transients The Attempt at a Solution [/B] from here, the solution is obviously wrong because from the solution, its alpha should be -300 and not -0.4...and from the...

Homework Statement For number 3,4,5 https://s4.postimg.org/qbp3xzq65/IMG_1092.png https://s22.postimg.org/u220j60sx/IMG_1093.pngHomework Equations Centripetal force = m v^2/R T = centripetal force + w Sigma F = m.a The Attempt at a Solution Number 3. Find the v at D point using...

I am almost done with a BS in physics with focus in nuclear engineering and engineering. My classes have been all the normal BS physics classes as well as nuclear physics with kranes book, two classes with Lamarsh's books on nuclear engineering as well as the blue bible (deuterstadt and...

1. The problem statement, all variables and given I do not have a clue where to get the information to built a DC motor with four electromagnets Homework EquationsThe Attempt at a Solution

Homework Statement HI! I'm in need of some help to come with an interesting physics-related topic for a short, five-minute presentation. We'll be graded by our ability to speak well rather than our physics knowledge, so I want to talk about something simple, straight-to-the-point and not too...

One big coincidence of thermodynamics is that automobiles are usually powered by an Otto cycle This cycle consists of an adiabatic compression (the cylinder compresses), isochoric compression (the fuel ignites, increasing the temperature in too short a time for the piston to move), adiabatic...

I am studying to about maxwell's equations on the electric and magnetic field. First of all, just do the example and exercise: https://www.princeton.edu/ssp/josep...ide-to-maxwells-equations-D.-FleischLEISC.pdf I have this dipole antenna...

[Note: Thread moved to homework forum by a moderator. shk, please post all homework questions in the homework forums in the future and be sure to use the template provided when creating a new thread therein.] A do-it-yourself company is advertising a wind turbine that they state can deliver a...

Homework Statement An infinite metal plate has a surface density of charge σL=-6μC/m² , Left side and a surface density Of load σR=+4μC/m² , in the right side. A Gaussian surface In the form of a circular cylinder, with area A 12 cm², is Located with the left side inside the plaque and a thin...

I am interested in breakthroughs in technology, physics and chemistry. Every once in a while I will post a challenge question to see if anyone has ever been confronted with this challenge or has experimented in that field.

How do I find the total potential energy at the highest and lowest points of oscillation without velocity or time?? I do not believe there is any air resistance, only gravity. I also already have the elastic potential energy and the gravitational potential energy.

< Mentor Note -- thread moved to HH from the technical math forums, so no HH Template is shown > I've encountered 2 problems in a row that involve lifting water out of tanks and finding the work needed. I am getting the incorrect answer. w = ⌠ab pgA(y)D(y)dy here is one of the problems: A...

Hello there! I am a newbie on the physics forums. I saw a thread which I wanted to answer because I had a better answer than the one given in that thread but the thread is closed and it is written there that 'you have insufficient privileges to reply here.' How do I get sufficient privileges...

In the movie wanted, the characters inside the movie can curve bullets by swinging the pistol, it is obvious it defies the law of physics. I know that a bullet cannot curve due to the law of motion, it is the same a sling (the thing that throw rocks) where the trajectory will always be a...

Homework Statement A hot-air balloon stays afloat because hot air at atmospheric pressure is less dense than cooler air at the same pressure.If the volume of the balloon is 500 m3 and the surrounding air is at 60◦F. What is the maximum load (including the weight of balloon, but excluding the...

Hey everyone, I'm writing a paper about major events/turning points and wanted to cite a scientific principle. Does anyone know if there is a physics (or any scientific) principal that refers to major turning points or the specific steps that lead to a certain outcome? Thanks so much!

Can someone please help me out with this tough problem? 1. Homework Statement A ball rolls on a turntable without slipping describe the balls motion in terms of (x,y) for a function of time. (The turntable spins at a constant rate) (This all the information that the professor gave us.)The...

Homework Statement A radio broadcast antenna is located at the top of a steep tall mountain. The antenna is broadcasting 104.3 FM (in Megahertz) with a power of 5.00 kilowatts. What is the peak intensity of the signal at a receiving antenna located 25.0 km away? Homework Equations Honestly...

Homework Statement A ball of mass m falls from height hi to height hf near the surface of the Earth. When the ball passes hf, it has a speed of vf. Ignore air resistance. Consider the system T which consists of the ball only. Write an expression for each of the following quantities in terms of...

How is this done in practice? I know that in GR the gravity is believed to curve not only space, but also time, and this prediction has been confirmed somehow in practice. How can we measure that? Because as far as i know, there is no device that actually measures time, but instead measures a...

I have read that Feynman Lectures on Physics is pretty good; however, I also read it isn't a replacement for a good textbook. So I wanted a good physics(high school level) textbook that I could read Feynman Lectures on Physics along beside it. Regarding mathematics, I have completed Calculus I...

I am starting a Phd in statistics this year at Montréal University (CANADA). Discussion about physics and quantum mechanics are my interests. THanks to all!

I am not sure if this is the right place to ask it, but this is a question that I thought today, and it gave me some curiosity to understand. Imagine that a car will curve, we can say the turn is a bit tight , what are the factors that can help it to flip? I was wondering about some aspects...

If I displace an object at rest in space by giving it a force F in X direction and the object tends to move forever, will the work done be infinite? Knowing that work done = force*displacement . Since the space has no external resistance (unbalanced force) to stop the object from moving , making...

Hi I am studying physics, and now considering the idea of taking a minor, my question is whether preferred to take minor in computer science or business ad. As for job opportunities. Thanks

Hi all. I am studying civil engineering BS.But I am so interested in astrophysics.Can i have physics graduate and PhD. If I can do this, what should i do to make my dreams come true. Please be a light for my path. ( Sorry about my English)

A block of mass 9kg is initially at rest at the top of an inclined plane of ramp length 4m. -Assuming that the plane is frictionless, calculate the speed of the block at the bottom of the plane. -Now instead assume the a frictionless force of Ffr = 2 Newtons opposes the motion of the block...

I think about many times for few days, but I still can't find out the correct answer! Maybe my steps are somethings wrong, please advise me! Thanks! A copper rod, 0.4m long and 4.0mm in diameter, has a resistance of 550μΩ at 20℃. Calculate the resistivity of copper at that temperature. If the...

Homework Statement A 4μF capacitor is charged to a charge of 200 μC,and a 3μF capacitor is charged to a charge of 300μC. Both the capacitors are connected so that the positive plates are connected together. What is the total loss of energy in the process? Homework EquationsThe Attempt at a...

I want to learn high school physics and math but using the international curriculum I want to see everything taught at high school in those books from grade 9 to 12 any suggestion ?

Hello, Right now I'm doing a Final Year Project 1 which is Air Hockey. The different between our air hockey and normal air hockey are our air hockey is octagonal shape. but now I'm stuck at calculating the air pressure for the table. can you help us? again this is just a school project not...

I Am Wanting to Find out who Created the inverse square law.

What is the name of this Laboratory Instrument?

It appears in a end page of a book published in 1956, named as "Our Friend Atom", that describes the benefits of the atom. Here is the end page:

http://physics.stackexchange.com/questions/243457/about-the-formula-of-pendulum-simple a(t) = a0 * sin ( sqrt(g/l) * t * Pi/2 ) - [ k/(mll) * cos ( sqrt(g/l) * t * Pi/2 ) * t ) ] a(t) : the angle in instant t . t : time g : gravity . Pi = 3.14 k = Fixed (Friction ) l : longer of pendulum...

hi, i reallyt need help in this question. i tried this but i am not sure how to start this, so if you can provide me little help i will really appreciate it its based on OP AMP circuit thanks guys

What is the difference between "Physics" (1 volume, 1156 pages) and "Fundamental University Physics" (3 volumes) by Alonso Finn? Is the former 3 volumes bound as one or a revised edition?

Homework Statement A chain of length L and uniform mass per unit length ρ is suspended in a uniform gravitational field. The potential energy U[y] and length l[y] functionals of the chain can be written in terms of y(x) as follows: U[y] = ρg*Int(y(1+y'^2)^1/2 dx) l[y] = Int((1+y'^2)^1/2)...

Homework Statement Hello! I have a physics homework question I just need help at! What I am supposed to do is calculate the value for free-fall acceleration, ag, for each of my trials that I did in my lab. I supposed to use the equation for the period of the simple pendulum, T=2π√l/g, but I...

So I have two questions relating to potential difference 1.An electron with a velocity of 5.0x10^6 m/s injected into a parallel plate apparatus through a hole in the positive plate. it moves across the vacuum between the plates, colliding with negative plate at 1.0x10^6 m/s. what is the...