Direction Definition and 999 Threads

Homework Statement 13. Find the magnitude and direction of the electric field at P due to the two charges shown. Homework EquationsThe Attempt at a Solution I have attached both the question, which involves a diagram, as well as my attempt at the answer below. My first question is regarding...

Homework Statement The problem is given above. I am struggling on the first two parts, where I am tasked with finding gamma and beta. Homework Equations For spin one half states in arbitrary directions, I know that psi = a*|n;+> + b*|n;-> . |n;+> = cos(theta/2)|+> +sin(theta/2)*ei*phi|->...

Homework Statement why the shearing force acting on the object in the first diagram is in different direction , while in the second photo , it's in same direction ?Homework EquationsThe Attempt at a Solution in my opinion , it should be in different direction , because the shearing force must...

Homework Statement why the resultant force on blade is acted downwards (toward A)? why shouldn't it be slanted upwards ? since the horizontal component of the force acted 2.12kN to the left , and 0.735kN upwards , we would get the resultant force acting slanted upwards , right ? Homework...

Hi All, I'm trying to think through a problem and was hoping to ping the community for guidance. Suppose you have a beam that's symmetric about 2 axes (like a u channel or a triangular extrusion). Is it better to load the beam in compression on the side with material furthest away or should you...

I have been under the impression that application of a magnetic field will quantise the z component of an electrons spin in that direction. I see this as a physical process, but Is this incorrect as it is often described as a measurement of a random variable/ wavefunction collapse? I am familiar...

I have a set-up where there are multiple conductive wires separated by insulators placed parallel to one another and current ##I_w## is flowing within each conductor(all currents are parallel and equal),they create a magnetic field and I believe would add up like this diagram: The current is...

I am finishing high school this year and i want to be a theoretical physicist. My academic result in mathematics is not good throughout last 5 years. But physics is my dream. I want to overcome every obstacles. I think i am not bad at mathematics but the reason behind my bad result was lack of...

Hi all, Can anyone please help me out with the direction of friction in a case where there is a smooth spherical body pure rolling on a rough surface? What is the direction of friction? Also, is it possible to have pure rolling without friction? Thanks SD

Homework Statement Vector A⃗ has a magnitude of 20m and makes an angle of 30∘ above the positive x axis. Vector B⃗ has a magnitude of15m and is oriented 60∘ to the left of the y axis. Find the magnitude of A⃗ −B⃗ . Find the direction of A⃗ −B⃗ . Homework Equations sin 150 = sin 30 = 0.5 cos...

Homework Statement KVL for a RLC circuit given current direction and polarity of a resistor? Here is the diagram of the circuit: Homework Equations KVL Sum of voltages equal zero The Attempt at a Solution I am actually looking for the voltage across the inductor (VL), so I decided the...

Why does the polar jet stream flow counter-clockwise around the Earth (as viewed from the north pole)? It seems that since the air at the north end of the Ferrel Cell and the south end of the Polar Cell rises, the Coriolis effect would cause a circulation in the clockwise direction.

Homework Statement Given the initial velocity of 6m/s[North] and the final velocity of 3m/s[East], how would you find the change in velocity? Homework Equations Change in velocity= final velocity- inital velocity The Attempt at a Solution [/B] I don't know how to do this. I know that if the...

Dear All, I have been offered to chose a direction for the MSc thesis in Theoretical High Energy Physics; 1: SUSY 2: SM 3: BSM 4: QFT in curved space etc 5: Quantum Gravity etc can anyone advice me which would be a better choice in getting a Phd position later? I don't want to chose something...

I understand from my classes that, when looking to calculate the electric field of a charge we can use the electric field measured in its rest frame to find its electric field in the lab frame (where the charge is moving). The gamma factor changes the value for the component electric field if it...

Hello, Can you tell me what is the difference between direction and dimension?

Will epsilon delta test fail if curve changed direction within the +/- delta of the limit point? Is there a scenario where no matter how small we pick delta to be, the frequency of the graph changing directions is always going to be a higher than delta's distance? In that scenario the limit...

Homework Statement m=25 kg, F1=88N[E55N],F2=54N[E], mu (coefficient of friction) = 0.350 Homework Equations FNet=F1+f2-Ff The Attempt at a Solution 88cos55 + 54=104.47, 88sin55+0=72.1. dheta=tan inverse (72.1/104.47)=34.6 degrees, what direction is Ff is my question and I would appreciate a...

Hello. Please see the attached picture first. For typical battery (nothing but capacitor), current direction is clear as electrons can't not flow across the two plates in battery so they only choose wire as a path from cathode to anode. But in transformer (+ and - sign represents voltage at...

I was confused about this example from a book. After putting in some numbers I got the forces circled in green and blue to be negative. Does this mean the directions for the forces shown is incorrect, and so I should switch the directions before calculating the reaction forces in the bearings (x...

This isn't actually a homework problem, but it is an example in a my textbook that I have a question about... imgur link: http://i.imgur.com/2OglMH4.png Ok, I wanted to clarify some things. I understand that current flowing from a positive terminal to a negative terminal represents a...

Consider a system with a mirror axis (bulk projected surface), I want to know the direction of spin polarization on the mirror axis. The result is that the spin is perpendicular to the mirror axis, but I don't understand the reason. If someone have related references, please recommend to me...

Why does Lorentz force have that particular direction? Why is it perpendicular to the magnetic intesity and the current? Is it cause of some photons' reactions? Thanks

how to find direction of hinge force? for example ,if a disc is hinged at a point on it's circumference and is exhibiting a rotational motion due to gravity,what is the hinge force?

Who do I know the direction of the current flow, when I make nodal analysis?

Hello Everyone. I recently studied the Einstein special theory of relativity. I studied the thought experiment where a beam of light is thrown from a moving spaceship in the direction of its motion and the distance after a certain time interval was different from perspective of a man on...

[Split off from this thread] I think that the force is always repulsive. I think that an electron would have to travel faster than c for it to become attractive.

Homework Statement The truss supports a sign board as shown in the figure. Calculate the reactions at A and the force in the member FG produced by the horizontal wind load of 60lb per vertical foot of a sign. Homework Equations ΣFx=0 ΣFy=0 ΣM=0 The Attempt at a Solution Everything is right...

Homework Statement A rod that is fixed to a vertical wall is attached through the middle of a solid disk. A piece of the disk crumbles off when the disk is spinning and rises vertically. The system is the chip and the spinning disk. Assume no friction. A. How does the direction of the angular...

Homework Statement I am not a student, but one poster was kind enough to answer my stupid question last week, and I was wondering if anyone would mind if I posted another stupid question. When an object is moved in a specific direction, how is the direction of momentum stored or recorded. By...

please explain why? Take 2 cases,and explain how is the direction of friction different in these 2 cases. CASE 1:uniform circular motion CASE 2:non uniform circular motion my thought was,friction opposes relative motion,so it must be tangential to the particle at each and every point. i very...

Homework Statement Write down the (real) electric and magnetic fields for a monochromatic plane wave of amplitude Eo, frequency w, and phase angle zero traveling in the direction from the origin to the point (1,1,1) with polarization parallel to the xz plane. I understand how to write the...

Homework Statement I am in Intermediate Electricity and Magnetism, and am working on review problems. I have a potentially very silly question: What physical direction is "horizontally north" (and similarly "horizontally south")? This seems like a counter-intuitive description to me (90...

Consider the following circuit (arrows represent current direction) : How does one determine the direction of the current in the middle branch ? Would it be correct to assume that : - if emf 1 > emf 2, current directionin middle branch is up, - if emf 2 > emf 1, current direction in middle...

I am confused about the concept of pressure force. Let's say we have some pressure acting on a flat plate. Would the force associated with this pressure be oriented into or out of the plate? Intuition obviously tells me that the pressure force is acting into the plate, but the math appear to be...

Hi Guys. I catch myself with confused a little bit of friction and physics. It's really simple to understand if it's a 1 box. And then you know that friction is opposed the motion. But it's little complicated for me in those cases : Case 1 : I assume that we will push the box 1 to right...

Homework Statement an object is sliding on an elliptical hill shown in picture. what is the direction of (inertial) centrifugal force at each moment? Homework Equations F=mv^2/r The Attempt at a Solution I think it should be towards the center of ellipse and value of r in the formula varies...

Homework Statement Given the following diagram: When examining the FBD for member AB how does one determine the direction of friction at B? If surfaces B and C exhibit friction. Homework Equations N/A The Attempt at a Solution I know that impending motion for post BC is in the direction of...

I have spent quite some time trying to get this, can someone please help me understand this? A plank is being pulled by a constant force F, it rests on top of two identitcal sylinders - there is rolling without slipping. What I don't understand is, why does F(p) - red arrow force, affect the...

As I see it; static friction is what provides the centripetal force, but does it do anything else? When the brother applies tangential force, what will happen with the static friction, because I assume it will start to provide less centripetal force because the tangential speed of the child...

Homework Statement Hi all, how do I know how the current direction are through each elements after solving a circuit (finding node voltages w.r.t GND)? I think my understanding in electricity is rather incomplete. For example, I know that current should flow from a higher potential to a lower...

Homework Statement [/B] A block of mass 2kg is accelerated by the two forces F1 = 8i + 3j and F2 = -5i - 7j, (a) What is the net force on the block in unit vector notation, and what is its magnitude and direction? (b) What is the magnitude and direction of the acceleration?Homework Equations...

Hi all, please help me here! Im confused, is direction of angular velocity perpendicular to the plane of motion, or along the plane of motion?? From hyperphysics - http://hyperphysics.phy-astr.gsu.edu/hbase/rotq.html -...

Hi, I wish to make Ni5Ga3 for use in an experiment, it needs to be in powder form. Please could someone direct me to a place where the methodology can be found? I usually order chemicals online, but my supplier (Sigma) does not have this compound so I need to make it. Also I need to consider...

Hello, My question is about using vector components to find a force in a particular direction. I already have the answer, I just don't understand it and would like an explanation if anyone has one. If I have two vectors with radial velocities (in this case it's measurements of ocean current...

Homework Statement the question states: "wo forces act on an object at an angle of 75 degrees. One force is 195N. the net force it 225n. determine the second force that it makes with the net force" Homework EquationsThe Attempt at a Solution I tried finding the second force by finding the two...

I am having issues figuring out how to do the "in the direction of the vector" part of my problem I have found the equation of the tangent line but i do not know how to the the next part. My question asks: Find the equation of the tangent line to the surface defined by the function f(x,y) =...

I am wrapping a transducer coil and had a question with the winding direction. Let's say that I am wrapping the wire around a bolt in a clockwise direction. After I reach the halfway point of the wire, if I then reversed the direction I am winding to counter-clockwise, what would it do? I am...

Homework Statement A flexible wire loop has a radius of r = 0.178 m and it is inside a uniform magnetic field of B = 0.332 T. The loop is grasped at points P and Q and stretched until its area is zero. It takes 0.146 s to close the loop. Homework Equations EMF = ∆Phi/∆t Phi = magnetic flux...

in simpleton's terms, a tokomak magnetically confines a circulating plasma. I assume the plasma circulates for the same reason that electric current flows in the presence of a changing magnetic field. By looking at the design of a tokomak, I would guess the donut magnets are activated...