Movement Definition and 636 Threads

Lately I've started learning about fuel cells, particularly proton exchange membrane fuel cells (PEMFC), and a fairly basic question that has been bugging me is: Since the cathode is positive, it is clear why the electrons flow through the load and to the cathode, but why do the...

Homework Statement Imagine you have an unflatable closed cube (z x z x z) which is connected to a chamber with a constant pressure of 6 bar (so the pressure in the box is also 6 bar). The box is hanging on a wire in a room in which the pressure is 1 bar. At t=0 a small part of the bottom of the...

Is there a formula I could use to determine how far in a medium a seismic wave would move if I hit one end of it with a hammer? I know the density of the rock and the force of the hammer.

I know that current flows in the opposite direction of electrons but I'm confused as to whether it is the movement of holes like in a semiconductor or if there are actual positive particles flowing that way.

Can a person suspended in space with nothing to push off of, turn themselves around?

I wish to give a vertical movement to a heating plate. How can I do it?

Is the movement of a mass affected by its curvature in spacetime? For instance will a forward moving planet diverges from its original straight line path due to the curvature of spacetime cause by it?

Hello, I would like to get help in solving a problem. I will describe what happens and what I want to know and hopefully someone can help me. We have object A that has to move from starting point 0 to point 1 in a linear movement. There are 2 forces acting on object A in opposite directions...

Homework Statement Two identical particles with $$ m=4,5 mg $$ and $$ q= 30 nC $$ are moving in vacuum in same direction. the paricles facing each other the time of the movement O --> <-- O like this.The time their distance is $$25cm$$ Homework Equations Which will be the minimum distance...

Homework Statement Hi everyone, I am doing a lab currently (and it looks like a few other people on here have had similar questions...) and I'm having trouble with one of the concepts. I had to drop a ball from a height and measure the movement with a motion sensor, which was graphed with the...

I am moving a small glued mirror (~10 gram) attached to a piezoelectric stage: http://www.physikinstrumente.com/product-detail-page/s-330-300700.html The mirror moves back and forth for a few milliseconds using a PID control loop, the range is about 2mrad. I want to increase the angular...

So our professor showed us wave patterns on a vibrating plate, by sprinkling powder over it. I'm curious as to why it behaved as it did.The powder moved to nodes, but I'm not sure why. I think it just gets bounced around until it lands on a node, which is stationary, so it then stays there. Is...

Homework Statement - A Dragster at the starting line accelerates at 8 m/s^2 to the finish line. If it took 4.6 s, how long is the track? - The Dragster deccelerated to a stop in 100m. How long did it take?Homework Equations x = 0 + 1/2at^2 The Attempt at a Solution The first part of the...

In my course there's a chapter with the mathematical explanation to find the real expression and localisation of a free particle with the superposited wave function. The same is used to explain the movemement of a wave packet (which is a free particle). I've worked out almost all the math behind...

Hello, I want to create a motion using electricity, using the cheapest means possible (DIY). Basically I'm trying to rotate an object 90degrees when the current is on, and back to its original position when the current is off. The questions are: 1) Is this possible? 2) Can this be done using...

I was wondering, since the Earth is constantly moving around the sun, the sun is moving around the milky way, and the milky way is moving through space (and for all I know the milky way might also be rotating around our local group, cluster, super cluster, etc.), how do we know how fast...

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown. Initial work is shown in the attachment. > Hello, l need to find the acceleration in the D point but i don't know how. the 2 circles turn in the same speed ( pi rad/s). I use a simulation...

How exactly does light move through space in terms of EM radiation and photons. What I'm confused about is the electromagnetic field. How does it oscillate, and in which directions? Also do photons have Electromagnetic fields associated with them?

This is something I've wondered for a long time. In discussing time dilation in SR, you often hear something along the lines of, "If you looked into a spaceship traveling near the speed of light, you'd see the astronaut inside moving in slow motion, the hands on their watch ticking slowly..."...

Homework Statement Hello there, So I have a problem that I can't seem to figure out on my own. I have no background in physics (I haven't taken a physics course as of right now,) but my robotics team requires some math. I need to find the equation for moving something with a mass of 1.5kg...

Assuming the duration of a second didn't change, how fast would we age and die if the Earth wasn't moving, the sun wasn't moving, the galaxy wasn't moving etc etc? All this speed allows us to live the duration that we do right? So if it all stopped, how fast would we be born, age and then die?

I need to purchase a device that will push something forward and backward continuously, in order to make wings flap like a bird. Linear actuators seem to be the right thing to buy, except these require pressing buttons to go forward and then back. What can I buy/what can I do that will allow a...

Einsteins special theory of relativity states that time passes differently for different observers. Basically the faster you travel the slower you aged. So I assumed this means to aged the fastest, you don't move. We also know Earth is moving around the sun. The solar system is moving upward...

Hi guys Do electrons move from high to low potential or from low to high potential I think the first one ia right because when electrons are attracted to the negative terminal they have maximum potential energy

Homework Statement A particle is in the ground state of a L-box. At t = 0 the wall at x = L is suddenly moved to 2L. (a) If an energy measurement is made after the wall is moved, what is the probability of measuring the energy to be that of the ground state of the new box? (given solution...

Does Magnetic Field (=/need) electron spin + movement of charge? A proton can create a magnetic field too, but does it have spins as well? Hmm super confused. What is a spin?

I don't know much thing about rays. When I was studying Rutherford experiment, I saw that nucleus scattered the alpha rays with Coulomb forces, and naturally the opposite forces effect the nucleus. So do the nucles of atom moves to the direction of alpha rays' first direction?

Can something even exist without energy? And if it can will it truly not move?To be clear I know E=mc2 but can something exist without any movement?

1. Homework Statement You are standing on side of road and ambulance drives by. Smallest distance between you and ambulance is 4m. Ambulance v=10m/s^2. You have 2.2 GHz radar. Ambulance travels 100m with center of straight line directly across from you. Compute exact doppler shift by taking...

Enjoy! (Yes) MZuSaudKc68

please delete this post Hello, Accidentally I have noticed a strange behaviour using two different magnets, which I would like to discuss. The picture shows a disc magnet (shown also in the right to see the magnetization) with it's N facing upwards. Onto the disc magnet N side, a cylinder...

Thank you in advance for your help! Consider a lifter performing a bench press. The weight of the bar is 225 lbs. Assume the duration of the entire movement from the lowest point to the highest is 1 sec., and that the bar will move a total of 2 ft. from the lifter's sternum to the height of his...

Hello, I know that the movement of a charged particle in space or a fluid caused by an electric field is accelerated(a = F / m) by the Coulomb force(Fc = k q1 q2 / d^2). And the Kinetic Energy of the particle is calculated through this equation ΔKE = q ΔV. But does an electron accelerate in a...

Homework Statement Determine the minimum value of the force F for which the systems start moving. Assume M1 = 1kg, M2 = 2kg, Us = 0.3. Solution: F = 9; F = 6N My problem is that i don't know the forces acting on wheel. Homework Equations The Attempt at a Solution M1 : F -...

I've recently read that the electrons move relatively slowly to what I had previously thought through a metal. That the "drift velocity" is slow, but because the electrons are plentiful, they can pass down the signal very fast. Near light speeds. Could someone explain what I'm missing and this...

At home I have a series of small square fridge magnets (about 25mm by 25mm and about 1mm thick). If I select two of these fridge magnets and place them together then, as you would expect, they attract one another. However the interesting observation is that sometimes the fridge magnets are only...

I am trying to understand this apparent "paradoxes" but probably i am missing something important. Imagine that accourding to stationary observer on Earth two twin cats are moving in the opposite directions with speed -v and v. When the two cats meet the stationary observer at the beginning O...

Please Solve this problem Book answer The velocity components are x = 0.50 m/s y = (0.40 m/s)/sqrt (2) east and (0.40 m/s)/sqrt (2) south, for a velocity relative to the Earth of 0.36 m/s, 52.5 south of west. Ok I think these components are of an angle of 45 º but whwn i Calculate from...

Dear all, is there anybody knows how to set a 2 degree-of-freedom movement in ANSYS Maxwell 2D transient model? I have two fixed current-excited coils and a free magnet. The magnet should be able to move in a 2D space under the Lorentz forces. However, there are only translation and rotation...

Homework Statement A stone tied to a rope rotates in a vertical circle. prove that the tension in the rope at the lowest point is 6 times the stone's weight bigger than at the highest point. Homework Equations Potential energy: E_P=mgh Kinetic energy: E_K=\frac{1}{2}mV^2 Radial force...

Homework Statement Can't seem to upload the figure in my workbook so I'll describe it. A metal bar is placed on 2 rails that slope up with a gradually increasing tangent. The bar has a higher conductivity than the rest of the apparatus. The 2 ends of the rails at the bottom are connected to a...

I read that based on temperature , electrons have kinetic energy in metals so they randomly move around the ion lattice. when we apply current to a room temperature conductor, the electrons being charge carriers align and form current? but what happens in the plates of a capacitor , when the...

Homework Statement A particle rotates counterclockwise in a circle of radius 4.4 m with a constant angular speed of 11 rad/s. At t = 0, the particle has an x coordinate of 2.9 m and y > 0 . Part 1: Determine the x coordinate of the particle velocity at t = 1.22 s. Answer in units of m/s...

C# Windows Form "Game": Movement All I wanted to do was to make a block move right/left across the window. I'm using VS 2010. No compiler errors and when I run it, it doesn't respond to any input. using System; using System.Windows.Forms; namespace Game { public partial class Form1...

Hello I'm trying to solve the following problem: "Find the equations of movement of a particle of mass m that slides on the inner surface of a spherical container given by the equation x^2 +y^2 + z^2 = 1, z≤0" I know I have to use F=ma and I've tried derivating the equation but I...

Homework Statement 4 electrons are moving due to electric forces. Find their velocity when they are very far away from each other, if initially they were on a square's (side length a = 20 cm) vertexes. Homework Equations F = \frac{kq_1q_2}{r^2} k = \frac{1}{4\pi\epsilon_0} The...

Homework Statement . Consider the system of ##N## masses shown in the figure (see picture 1). a) Using the approximation for small angles, write the equation of transverse movement for the n-th particle. b) Propose a solution of the form...

Hello there, I've for a long time thought that movement energy is transferred through collisions, one atom hits another and transfers it's momentum (Billiard balls). When they're stuck in a rigid structure like a metal, they vibrate until the energy of vibration exceeds the energy of their...

I'm stumped at how to approach this problem and was hoping someone could enlighten me. If I had sold $100 of a product and made a 20% profit up until a specific day. The next day, made three sales; A) $20 making a $5 profit B) $50 making a $30 profit C) $30 making a $15 profit. So...

Homework Statement A biologist looking through a microscope sees a bacterium at r1→ = 2.2i + 3.7j -1.2kμm. After 6.2s, it's at r2→ = 4.6i + 1.9kμm. a)What is it's average velocity b) What is its average speedThe Attempt at a Solutiona) v→= Δr/Δt v = (r2-r1)/6.2 = (2.4i - 3.7j + 3.1k)μm/6.2s =...