Component Definition and 568 Threads

Hello Physics Forums! My problem is as follows. I have a device that produces heat via Nichrome coils. I want to heat another small piece of metal (in this case stainless steel) with those Nichrome coils. I need to reach 175 degrees C, and so far I haven't found a readily available thermal...

Hi everybody, I want to ask a question about the dipole moment vector ##\vec{d}##, with components expressed in the molecule-fixed axis. By permuting identical nuclei that compose a rigid molecule, I know how ##d_x##, ##d_y##, ##d_z## change. But when dealing with non-rigid molecule, I no...

Is there a single optical component that will do the following? Do nothing to the horizontally polarized input, but rotate the vertically polarized input by 90 degrees, so that both beams finally emerge with the same polarization? I am looking for a single element that will replace the...

Given the metric of the gravitational field of a central gravitational body: ds2 = -ev(r)dt2 + eμ(r)dr2 + r2 (dθ2 + sin2θdΦ2) And the Chritofell connection components: Find the Riemannian curvature tensor component R0110 (which is non-zero). I believe the answer uses the Ricci tensor...

What happens to one of the components when it is at VERY low concentration in a two component alloy? My problem: Uranium decays to thorium. The thorium isotopes it decays to typically have pretty short half lives. During casting, it is well known that thorium fractionates to the slag, crucible...

Hello, I'm a beginner at quantum mechanics. I'm working through problems of the textbook A Modern Approach to Quantum Mechanics without a professor since I am not going to college right now, so I need a brief bit of help on problem 1.10. Everything else I have gotten right so far, but I am...

Suppose you periodically receive samples of a periodic waveform at fixed instances in time Δt. It is known ahead of time that the periodic waveform will have a fundamental frequency component of 50Hz or 60Hz, but perhaps with some higher order harmonics present. What is the easiest way to go...

Homework Statement Please don't make me post the entire question. If so, can I take a picture of the example in my textbook? I am looking at an example in my textbook where we are to check Stoke's theorem After doing the cross-product of del cross v I get (4z^2-2x)[x hat] + (2z^2)[z hat]...

Homework Statement Show $$\frac{\partial \det(A)}{\partial A_{pq}} = \frac{1}{2}\epsilon_{pjk}\epsilon_{qmn}A_{jm}A_{kn}$$ Homework Equations ##\det(A)=\epsilon_{ijk}A_{1i}A_{2j}A_{3k}## The Attempt at a Solution $$\frac{\partial \det(A)}{\partial A_{pq}}=\frac{\partial}{\partial...

Homework Statement A cyclist rides along a road up an incline at a steady speed of 9.0 m s–1. The mass of the rider and bicycle is 70kg and the bicycle travels 15 m along the road for every 1.0 m gained in height. Neglect energy loss due to frictional forces. Calculate the component of the...

The particular equation I would like to see solve is: ##\sin\theta\frac{d}{d\theta}(\sin\theta\frac{d\Theta}{d\theta})+\Theta(l(l+1)\sin\theta-m^2)## The solution for this equation is the following associated laguerre polynomial...

$\tiny{s6.12.25}$ $\textsf{If $v$ lies in the first quarter and makes an angle }\\$ $\textsf{$\pi/3$ with the positive x-axis and $\left| v \right|$=4} $ $\textsf{find $v$ in component form.}$ \begin{align} \displaystyle v&=\langle 2\sqrt{3},2\rangle \\ \end{align} this is probably correct...

Homework Statement The apparent total magnitude of a triple star is ##m_0 = 0,0##. The apparent magnitudes of two of its components are ##m_1 = 1,0## and ##m_2 = 2,0##. What is the apparent magnitude of the third component? Answer: 0,9 Homework Equations Since according to Norman Pogson...

Hello. I have a following C programming language code that blinks an LED ON and OFF. #include<bcm2835.h> #define LED RPI_GPIO_P1_12 int main(int argc, char **argv) { if(!bcm2835_init()) return 1; bcm2835_gpio_fsel(LED, BCM2835_GPIO_FSEL_OUTP); unsigned int delay(1000); while(1)...

Homework Statement $$ E = -\vec{v_{obs}} \cdot \vec{p} $$ Where ## \vec{p} ## is the four momentum, and ## \vec{v_{obs}}## the velocity of the observer. Homework EquationsThe Attempt at a Solution [/B] This was a stated result in a GR course. I look through my SR notes and find that I...

Homework Statement Homework Equations s=r* theta The Attempt at a Solution

[Mentor note: Thread moved from technical forums so no formatting template shown] Unfortunately, I'm completely lost with this question: 1. A particle is moving along the x-axis. Its position as a function of time is given as x=bt-ct^2 Derive an expression for the x- component of velocity...

Why during a banked curve is the horizontal component of the normal force considered as the net force and the centripetal force? The horizontal component of Normal force, N·sinθ, is not even ponting towards the centre of the curvature.

] I found in a textbook that the value does not change because the centripetal force is perpendicular to the tangential velocity. But I am confused, because a vector can have a component, which is perpendicular to the vector. So if the centripetal force is perpendicular to the tangential...

This is a question about the well known trigonometric problem of the wind triangle, but my problem is just the calculation of the head wind component. I don't know how to write a general procedure to find the angle between the wind and the speed of the aircraft (the so called ground speed)...

Hi, I've found a derivation of the formula for the relativistic momentum where they considered a car crashing into a wall in the system of the car and in an inertial system that moves parallel to the wall (and therefore perpendicularly to the movement of the car). They argue that since both...

Light is an electromagnetic radiation with two wave components that are perpendicular. Between these two perpendicular waves, where is the photon in this system.

Hey, So I've taken a course learning theory to mosfets, Jfets, transistors etc. Recently we did an amplifier project with a summing component as a final project. I chose which component pretty randomly. I'm a little misled as to which component is better in certain circumstances. BJT's are...

As I understand it one is forced to use 4-vectors since we require objects that transform as vectors under application of Lorentz transformations and 3-vectors do not (technically they do under rotations, but not under boosts). Equivalenty, if one starts off with Minkowski spacetime from the...

Homework Statement Verify that ##\partial_{\mu}F_{\nu\lambda}+\partial_{\nu}F_{\lambda\mu}+\partial_{\lambda}F_{\mu\nu}## is equivalent to ##\partial_{[\mu}F_{\nu\lambda]}=0##, and that they are both equivalent to ##\tilde{\epsilon}^{ijk}\partial_{j}E_{k}+\partial_{0}B^{i}=0## and...

In the above case, mgcos(theta) is the component of gravity perpendicular to the surface of the wedge. Considering all surfaces to be frictionless, the horizontal component of the normal force would cause the wedge to accelerate towards the right, and the horizontal component mgcos(theta)-the...

Hi, I have this math problem where I need to find the scalar component of acceleration at a given time under certain conditions. Usually these problems aren't bad for me, but this one has left me scratching my head. Its giving me ||a|| = 4 and (aT)(T) = 5i +5j -k I have the formula aN =...

Homework Statement Consider the rigid body in the picture, rotating about a fixed axis z not passing through a principal axis of inertia, with an angular velocity \Omega that can vary in magnitude but not in direction. Find the angular momentum vector and its component parallel to z axis (...

Consider the rotation of a rigid body about a fixed axis z, not passing through a principal axis of inertia of the body. The angular momentum \vec{L} has a parallel component to the z axis (called \vec{L_z}) and a component perpendicular to it (called \vec{L_n}). I have some doubts on...

Hey guys, I'm really stuck right now 1. Homework Statement Habitable exoplanet: Now we will include a convective heat flux (H), with H being proportional to the difference between the atmospheric and ground surface temperature, $$H=c_p(T_a-T_p)$$ with c = 1.2 Wm−2K−1. Calculate the temperature...

Homework Statement The truck is to be towed using two ropes. If the resultant force is to be 950 N, directed along the positive x axis, determine the magnitudes of forces FA and FB acting on each rope and the angle q of FB so that the magnitude of FB is a minimum. FA acts at 20° from the x-axis...

Homework Statement See photo attachment Homework EquationsThe Attempt at a Solution Ive begun by defining an x and y axis, followed by find the sum of x-components of the forces, and y-components. Followed by the magnitude of the resultant force. The only method i could think of was to find...

I have a Casio FH-20 camera. I tried looking for a schematic to no avail. Everything in the camera works fine except that it will no longer remember the date/time when the batteries are removed. I figured there was a lithium battery in the camera that went dead (it's about 8 years old, I...

Hey guys, I don't know if this question is supposed to be in the homework questions section, If it is then I'm sorry. I just want to know the name of this component (the one inside the red box). It looks like a flip flop, I'm not sure. I just haven't been able to find it on the internet and I...

I was going to make a modem uninteruptable power supply, and I was thinking (possibly over complicated) that I could have a relay with the solenoid that has a potential over the battery bank and the power supply, so there would be near zero volts potential when the power supply was on (and...

Homework Statement Homework Equations I know that the tangential accel is v = wr and that Centripetal = v^2/r The Attempt at a Solution For A, I thought it would be straight forward if I had the radius as well as omega. I know that the distance between A and B is 60in, but I don't think it...

Hi people, I have a lopper (the kind for trimming bushes or tree branches). I have it rigged up like the diagram below. The blades are on the bottom left. The bottom arm is straight while the top arm is at an angle theta. I have a load cell which is applying a constant force downward and...

Homework Statement An air-conditioning unit is fastened to a roof that slopes at an angle of 35° above the horizontal (Fig. 1.33). Its weight is a force on the air conditioner that is directed vertically downward. In order that the unit not crush the roof tiles, the component of the unit’s...

What is this component in the middle with the two broken connections? It is on an instrument for measuring extensional viscosity that is not working. It looks like a power amp and a wire wound resistor on the same board got real hot. Don't know if there is any relationship to the two broken...

Hello. In class today, we studied conical pendulum but I was confused at the part about its components. In all the diagrams ( http://dev.physicslab.org/img/90c0fb7a-ffb4-4573-b389-b50a559732c8.gif ) if shows The x-component as being sine, but I always thought x-comp was cos?? (...

Why phi component is not taken into account while calculation electric field intensity due to line charge?See attachment for details.https://physicsforums-bernhardtmediall.netdna-ssl.com/data/attachments/74/74211-22d26b27211fd4b186955b890458804e.jpg...

Homework Statement Show that the component of the jerk along the line of centres of two gravitating bodies has magnitude 2G(m1+m2)r(dot)/r3. Homework Equations (Eq. 1) r(double dot) = - G(m1+m2)r(hat)/r2 (acceleration of body 2 relative to body 1) The Attempt at a Solution Sorry for the...

Hello all. Sometimes, when reading a physics book, I find it difficult to distinguish between the magnitud of a vector and the component of a vector. For example, take the weight force, with the positive z direction pointing upwards (that is, F= -mg k). Sometimes, people write F=mg referring to...

Homework Statement This is the force table lab that we are doing. F _1 = 300g @ 30^o F _2 = 450g @ 110^o F _3 = 400g @ 230^o F _4 = 270g @ 298^o Finding resultant force using Component Method 1. Express each force F1, F2, and F3 in unit vector notation. Take the origin to be at the center...

I am designing a custom socket for an application at work and I am concerned about the wall thickness in the area marked by the red box (see attached drawing). The socket will be used to torque a nut to 500Nm. I have a degree in mechanical engineering and I can do stress calcs on straight...

Homework Statement Basically I'm given a feed flowrate - 70,000 gal/day I know the weight percent is 35% and the component is Triethylene Glycol - density - 1.255g/ml Homework EquationsThe Attempt at a Solution So i did this 70,000 gal/day * .35 * (.0378mL/1gal)* 1.255g/mL = g of Triethylene...

Homework Statement Rather than retyping the problem, I've uploaded a screenshot here >> http://imgur.com/EB5MrtP Homework Equations Q_1 + Q_2 + Q_3 ... = 0 mc \Delta T = Q The Attempt at a Solution a. Q_{tea} + Q_{met} + Q_{cr} = 0 I converted the temperatures to K, so T_{cr} and T_{met} =...

Hello, given the figure above, how do I get the tangential and normal components of a vector in any plane by integration?

Homework Statement Why the force component of u nt 30cos30? The ans given is 30sin45/ sin105... Homework EquationsThe Attempt at a Solution

How does one derive the general form of the Riemann tensor components when it is defined with respect to the Levi-Civita connection? I assumed it was just a "plug-in and play" situation, however I end up with extra terms that don't agree with the form I've looked up in a book. In a general...