Direction Definition and 999 Threads

Homework Statement Homework Equations impulse = mv The Attempt at a Solution so i found the velocity of the blob of clay now i am trying to find the direction. i took the xcomponent initial stuff which was 0.04kg*4m/s*cos45 - 0.03kg*3m/s Then set it to the final x component stuff which i...

Homework Statement [/B]In this question, it asks for the magnetic field associated with the electromagnetic wave. Homework EquationsThe Attempt at a Solution The magnetic field is perpendicular to Electric field but it can be in either x or z direction...how do I choose the direction.I

Hello Here is the shadow of the edge of a screen. This picture is in one of Mr Feynman's books. (Http://www.feynmanlectures.caltech.edu/I_30.html) Of course, there is light interference in the edge of the shadow. It's normal. It's diffraction. Mr Feynman explains how to geometrically build this...

I am trying to work out the velocity of the ball in a loop in terms of theta from the horizontal (like a unit circle) as it loses contact with the track. And having a lot of trouble understanding this equation m*g*sin(theta) = m*v2/r and this explanation: The ball will leave the rail when...

Homework Statement We bind two batteries with voltage 2V and 1.7V with inner resistance 0.2Ω and 0.1Ω in parallel series in such way that we bind each positive poles and negative poles together. What current runs trough the circle? What is the voltage between contact points of the batteries...

Homework Statement Homework EquationsThe Attempt at a Solution I have already solved for the magnetic fields everywhere AND THE magnetic field at R>F = (U/2*PI*R)*(I2-I1) My only problem is i know i use the right hand rule to determine the direction of the magnetic field B as clockwise or...

When can we use the right hand rule to find the direction of a magnetic field from current? I know that it works for an infinite wire. Does it work for a finite wire? Where does it work and not work?

Homework Statement Referring to (b) in the picture above: What is the direction of the magnetic force on the electron? Homework Equations I use the right-hand rule where by putting your index finger in the direction of the magnetic field and thumb in the direction of the velocity, the middle...

Homework Statement Cart travels with a mass of 100kg in the 25m/s in the X-Direction and then 20m/s in the Y-Direction. What is the impulse? Homework Equations I = m*change in velocity The Attempt at a Solution I = 100(20 (j) - 25(i)) I = (2000 (j) - 2500(j)) kg* m/s Is this correct?

Homework Statement The problem asks to find the direction of the magnetic field at point P, which is at the center of 2 separate semi-circle wires that form a circle. The current in each wire flows in the same direction (to the right). I attached a picture below. Homework EquationsThe Attempt...

Homework Statement Homework Equations Angle of twist = TL/JG The Attempt at a Solution T & L is inversely proportional. But how can i start attempt the question? I think it this way: like moment=L*F, and torsion torque is like force, angle of twist is similar to moment (as TL are also...

Homework Statement Example 5.9 in Griffiths's Introduction to Electrodynamics 4th shows us how to find B of a very long solenoid, consisting of n closely wound turns per unit length on a cylinder of radius R, each carrying a steady current I. In the solution, he goes on to explain why we don't...

Homework Statement Hi I'm having trouble with a question that's asking me to calculate the precession rate for a spinning top. The trouble that I'm having is that I don't understand how the angular momentum points along the axis of the spinning top (picture attached). When I use the formula...

In general, the field lines points away from the positive charge and toward the negative charge. The answer is letter E, but the second part of the answer says, "the magnitude of q1 is less than the magnitude of q2". Is that because q1 is negative and q2 is positive?

I'm thinking about flying off in a spaceship that travels half the speed of light so I can, in effect, travel into the future, since everyone stuck on Earth will be going relatively slow and aging relatively faster than me. But my concern is that I don't know which way to go. Right now the...

Something was thrown with an elevation angle 60^{\circ}. Determine its velocity and direction after: a. \frac{1}{2}\sqrt3 second b. \sqrt3 second I tried solving the (a) question by substituting the angle to the equation y=v_0\sin\alpha t-\frac{1}{2}gt^2 and got 0 (the book uses 10m/s^2 as the...

If electrons are waves, what causes them to change direction and move up and down?

If there is a very very big(infinitely big) region of space where ## \frac {dB} {dt} = constant ## what would be the E field at any point? Obviously ## \nabla x E = constant ## but what after that ?

I'm confused by an apparent ambiguity in the direction the E field in Faraday's law: ∫ E°dl = - ∂/∂t ∫ B°da Faraday's law says the change in magnetic flux through an open surface gives rise to an emf equal to E°dl taken around the closed loop which is the boundary of the open surface. And...

Homework Statement Homework Equations The Attempt at a Solution Since Fel > mg , the particle will move up with acceleration

Homework Statement You enter an antique classic car road rally with your 1956 Studebaker Golden Hawk. The rally course consists of the following segments: travel north at 25.0 m/s for 30.0 min, then east at 32.0 m/sfor 40.0 min, and finally northeast at 30.0 m/s for 50.0 min. For the entire...

Homework Statement A Higgs particle of mass M is moving in the z-direction with speed $\Beta_H$c compared to the lab system. It decays to a b-quark ans anti-b quark, each of mass m. What is the speed and direction of the b-quark compared to the lab-system, if the Higgs system, (a) it is emitted...

Homework Statement In the picture 20.40, what is the direction of the current induced in the resistor at the instant the switch is closed.[/B]Homework Equations Right hand rules- Point thumb in direction of current and your fingers will curl in direction of magnetic field. Lenz's law. The...

I am reading the book "Several Real Variables" by Shmuel Kantorovitz ... ... I am currently focused on Chapter 2: Derivation ... ... I need help with an interpretation of a statement by Kantorovitz near to the start of Chapter 2 ... The start to Chapter 2 in Kantorovitz reads as folows...

Homework Statement The problem states: Determine the voltage labeled v in the following circuit: https://ibb.co/hz0Q37 The variable is the voltage across the 2 ohm resistor. The ground I chose for this example is located in the center of the circuit. Homework Equations V=IR I guess. The...

I was watching an excellent presentation of the theory of the Alcubierre warp given by Miguel Alcubierre himself at the 2017 Starship Congress (link below). At the 43:55 mark Alcubierre explains that the negative energy is located around the circumference of the craft in a toroid. I always...

Homework Statement A child is flying a large kite of mass 6.8 kg on a windy day. At the moment shown the tension from the string on the kite has a magnitude of 17.0 N and makes an angle of = 32.6° from the vertical, and the acceleration of the kite has a magnitude of ak = 7.72 m/s2 and makes...

Good day All! while trying to solve this question I use the right hand rule and according to it the Force should be directed outward (pointing toward me) but here is the answer that puzzeld me I really don't get why it is down , and would feel very grateful if someone can explain me the...

Homework Statement A child goes down a water slide. The slide is 9.0 m tall. She pushes off with an initial speed of 2.0 m/s (in the horizontal direction). If the slide is frictionless, how fast will she be going at the bottom of the slide? Homework Equations In the book, they use a...

Hi, I'm studying GR these days. But then I got to thinking about something about SR and got kinda stuck. I know that if a light clock is moving in the x direction(from left to right), the light beam has to traverse more space and then you will see this person's clock running slower in the...

Homework Statement The problem is simple, all I have to do is draw a voltage / time graph. The black ring is a conductor, its inner surface area is 0.01 m^2. The magnetic field points upward, B = 4T. 2. The attempt at a solution I understand what I have to do, but I'm getting the wrong +/-...

Homework Statement A shell of mass 12 kg moving horizontally at 320 ms^ -1 explodes into three fragments A,B and C, which continue to move in a common vertical plane. Fragment A: mass 2 kg continues at 450ms^-1,45 degree angle above the horizontal. Fragment B: mass 6kg continues at 400ms^-1...

Homework Statement A simple harmonic oscillator, with oscillations in the x direction, has velocity given by: $$v_{x} = (2.2 \frac {\mathrm{m}} {\mathrm{s}}) \sin [(6.9 \frac {\mathrm{rad}} {\mathrm{s}}) t]$$. Find the values of ##\omega , A, f , T ,## and ##\phi## Homework Equations $$v_{x} =...

Homework Statement Hello, I havre problem here relevant to an image I will attach. ''A cricket ball hit by a batsman moves with a speed of 6m/s along a straight line path PQRS, as shown in the diagram. When the ball is at R, a fieldsman starts to run in a straight line from T with a speed of...

Hi I have attached a picture here, of a solenoid with a copper block connected to a battery suspended in it. The current moving is clockwise, So the magnetic poles would be as shown. Now my problem always is this, I get so confused with this, I used Fleming's left hand rule to find the...

Homework Statement Given the following expression $$ \Psi(x,t) = A cosh(36 x^2 - 12 x t + t^2)$$ Determine whether this is a traveling wave and if so what is its propagation velocity and propagation direction? Homework Equations Wave equation $$ \frac {\delta^2 \Psi(x,t)} {\delta x^2} =...

Homework Statement -4.882L1+M1+2N1=0 L1-2.882M1=0 2L1-0.882N1=0 L1^2+M1^2+N1^2=1 How to solve for L1 ,M1 and N1 ? 0<L1,M1,N1<1Homework EquationsThe Attempt at a Solution

Homework Statement Compute ##\partial_n f## where ##n## is normal to ##f##, and ##f## lies in the ##x-z## plane and is parameterized by $$x(s) = \frac{1}{c} \sin (c s);\\ z(s) = \frac{1}{c} (1-\cos (c s)) $$ Homework Equations ##\partial_n f = \nabla f \cdot \hat n## The Attempt at a Solution...

When studying Fresnel equations in EM, I very often came across the following type of picture for a s-polarized incident wave on a dielectric interface (http://iqst.ca/quantech/pubs/2013/fresnel-eoe.pdf) : Many similar diagrams can be found on the internet, for instance...

$\tiny{\\ eb 4.d}$ $\textsf{If $v_x=-9.80$ units and $v_y=-6.40$ units,}\\$ $\textit{determine the magnitude and direction of $V$.}$ \begin{align*}\displaystyle magnitude&=\sqrt{(-9.8)^2+(-6.4)^2} =\color{red}{11.7047}\\ direction&=\arctan{\left[\frac{6.4}{-9.8}\right]}...

Homework Statement A diver explores a shallow reef off the coast of Belize. She initially swims 90.0 m north, makes a turn to the east and continues for 200.0 m, then follows a big grouper for 80.0 m in the direction 30° north of east. In the meantime, a local current displaces her by 150.0 m...

1. A crate resting on a rough horizontal floor is to be moved horizontally. The coefficient of static friction is 0.40. To start the crate moving with the least possible applied force, in what direction should the force be applied? a. Horizontal b. 24 degrees below horizontal c. 22 degrees...

1) Firstly, in the context of a dot product with Einstein notation : $$\text{d}(\vec{V}\cdot\vec{n} )=\text{d}(v_{i}\dfrac{\text{d}y^{i}}{\text{d}s})$$ with ##\vec{n}## representing the cosine directions vectors, ##v_{i}## the covariant components of ##\vec{V}## vector, ##y^{i}## the...

Homework Statement A force of 2.4N is exerted on a -1.8µC charge in a downward direction. What is the magnitude and direction of the magnetic field at this point? (The assignment sheet is called "Electrostatics Questions", hence the "Electrostatics?" in the title) Homework Equations Electric...

Homework Statement If you were to gain a few electrons and go running in Vancouver, what would be the magnitude and direction of the magnetic force that you would experience? Homework EquationsThe Attempt at a Solution So I was able to determine the magnetic force but my only problem is...

I want to understand why the reaction force of the short cable and link cable is in this direction? I want to understand it instead of memorizing. Your help would be much appreciated. Thanks in advance!

I have the following question considering frame dragging: A test mass starting at rest near a rotating mass or with an initial velocity pointing towards the center of the rotating mass will be deflected in such a way that it begins to move around the mass in the rotational direction. This is...

Homework Statement For the state of stress shown in the figure, normal stress acting on the plane of maximum shear stress is? Homework Equations Normal stress σn = σcos2θ 3. The Attempt at a Solution Plane of maximum shear stress is 45o relative to the max stress of 100MPa. So the total...

In this example (https://imgur.com/a/pTFIt) could i define F_1,2 in terms of r-hat_2,1 instead of r-hat_1,2?

Homework Statement Homework Equations The Attempt at a Solution does Vpa has the same direction as Vp? i thought Vp is tangent to the circular path that point P creates( perpendicular to vector Rpa) but from the figure, Vp doesn't seem to be tangent to the path, but Vpa does...