Frequency Definition and 1000 Threads

Homework Statement Homework EquationsThe Attempt at a Solution I found this solution for the nature frequency but here it does not include the Ball weight and centrifugal force in the moment balance equation about the pivot (O), it is wrong answer...is not it? I tried to solve the problem...

Homework Statement Consider a two-state system with a Hamiltonian defined as \begin{bmatrix} E_1 &0 \\ 0 & E_2 \end{bmatrix} Another observable, ##A##, is given (in the same basis) by \begin{bmatrix} 0 &a \\ a & 0 \end{bmatrix} where ##a\in\mathbb{R}^+##. The initial state of the system...

Homework Statement [/B] I messed up the original thread in terms of information, so I made a new better one. Ok here goes: I have a problem where a right circular cylinder with diameter .115meter and a mass of .03kg is rotating at 300 rev per min. Now an Ant which weighs .01kg collides with...

Homework Statement Hi I know my picture has 2 problems, but let's just focus on the first problem parts a and b. So for part a it ask for the final frequency after the ant landed, and part b is the kinetic energy difference. Basically the ant=.01kg, diameter of cylinder is .115m, the weight of...

Hello I am developing a low noise preamp and would like to change the roll off of my design to sharply decrease the gain for very low frequencies "1-5Hz". The results of my current design are as follows. I would need something that looked more like this.. I understand the simple equations...

I am having some difficulty understanding the Pound-Drever-Hall frequency stabilisation technique, when locking a laser to a stable cavity. As far as I understand: We emit the laser frequency, f0. This signal is modulated with sideband frequencies, ± fm. This is fired towards the Fabry-Perot...

Gravitational wave stretches and shrinks space. Why Laser light in Ligo arms changes frequency, and not wavelength.Is it some clear explanation? If even frequency would not be changed than spacetime is not changed, I suppose. What cannot be measured, cannot exist.

Hi there When a charge is accelerated it produces electromagnetic radiation. I was wondering if anyone knew the equation relating the frequency of emitted radiation to the size of the charge and the value of the acceleration. My understanding is that it relates to Maxwell's equations, but I was...

Homework Statement There's a horizontal thin wire whose mass is negligible and whose length is l=1m. It is strained with constant force F=10N. If we place a tiny pellet in the middle of wire (mass of pellet is m=1g) and then we bring wire out of equilibrium position (moving out of it's original...

Hi there My understanding is that any charge will produce some emf when it is accelerated..is this always true? What is this law called? Is there a simple equation to relate charge size, acceleration rate and resulting emf frequency? Many thanks

Hello. The collisional frequency is generally expressed by ν = nt×average of (σv), where nt, σ and v are density of target (atoms or molecules), collisional cross section of target and kinetic velocity of incident particles. σ depends on kinetic energy of incident particles I thought...

Hi there, I am in need of another's thoughts on this topic. I at first thought frequency is something that doesn't change and is inherent to the source, so then increasing the wavelength shouldn't lead to an increase in frequency, but an increase in speed. I realized later that this only...

Homework Statement Consider two parallel walls perfectly reflective placed at the distance ##d = 0.8 m ##. A ball, provided with a device through which are emitted continuously frequency sound waves equal to ##f_0=430 Hz##, is launched from one wall to another. It moves with constant velocity...

I understand what is Monochromatic frequency signals from https://www.physicsforums.com/threads/monochromatic-waves.570958/, but could somebody kindly give a brief explanation about "why does a monochromatic frequency signal result in poor PAPR (Peak to average Power Ratio) performance"...

Homework Statement A person stands in an open space listening to the sound from two speakers. The speakers generate sound with a frequency of 489.5 Hz, the speed of sound in air is 343 m/s. The speakers are 2.00 m apart and the person walks away from one of the speakers along a line that is...

Homework Statement [/B]Homework Equations I honestly do not know any relevant equations for this relationship. Well except f=v/2l. The Attempt at a Solution The only thing I could assume that it was was some sort of error , but I cannot find much material on the topic , so I was hoping to get...

can someone explain why high frequency waves contain higher energy? thanks!

I want to build a Resonant Cavity to play with frequencies around 100-700 mhz. I'd like to try different shapes, so I was thinking in using a cheap malleable material like aluminum foil. Questions: - I think one layer of aluminum foil might be too thin.. If I paste a couple of layers will do...

I'm trying to remember simple probability form high school. I'd like to know how the probability of anyone event changes with frequency. So for example the probability of getting one ace of spades is 1/52; what is the probability of getting at least one ace of spades if the card is put back and...

How do I know, how big of a voltage gain for an amplifier do I need, if I want to increase the input frequency from 250 Hz to 50 kHz? Thank you.

If a photon does not experience time, how can it change? Without change, how can it have frequency?

Homework Statement A body performaning simple harmonic motion has a displacement x given by the equation x= 30 sin 50t, where t is the time in seconds. what is the frequency of the oscillation? Answers are: A. 0.020Hz B. 0.13Hz C. 8.0Hz D. 30Hz E. 50Hz (correct...

Homework Statement [/B] A pure tone (sine) carrier signal of 440 Hz is frequency modulated by another sine wave of frequency 440Hz with an amplitude of 1760. (a) For the steady-state portion of the output signal generated by synthesis above, calculate: i) the deviation and ii) the Index of...

Hi everyone, As we move from left to right in EM spectrum the energy EM wave carries in creases as does the Frequency. Then why even after having a lot of energy waves can't penetrate hard me trials like rock. For example, Microwave aren't that good in penetration of tough objects but have...

Does the electric field strength required for field emission change with frequency? Better yet, at higher frequencies, is there a correlation with emission current?

The magnetic moment of protons precesses at a frequency ω0=γB0 about the static magnetic field. In order to move the magnetisation vector into the transverse plane the RF pulse must be applied at a frequency ω0. However, as B1 (the field strength of the RF pulse) is << B1 how is this possible...

Hi, A question popped into my mind which I've never thought of in 20 years of making music: when you hold a tuning fork against a simple resonator (a guitar body, a table, any object with some volume really), the resonator amplifies the tuning fork's sound and you hear the tuning pitch louder...

Hello, I performed an optimization and frequency calculation at the ub3lyp 6-311g level of theory. The compound has the formula C39H41PS2. Using Molden, I am having a hard time identifying the frequency corresponding to the stretching of a phosphorus carbon double bond present in the molecule. I...

Homework Statement I am studying for an Optics exam and in one of the practise tests is the following question: "Over what frequency range are Maxwell's equations valid?" Homework Equations Maxwell's Equations The Attempt at a Solution I've searched through my Griffiths Intro to...

Homework Statement Two waves of different wavelengths λ1= 1.5μm, λ2 = 1.63μm, are combined in free space Et = 1.5cos(k1x - ω1t) + 2cos(k2x -ω2t) Find the beat frequency Homework Equations (ω1- ω2) = 2ωm=beat frequency E02 = 4E012cos2(kmx - ωmt) The Attempt at a Solution I am quite stuck on...

Homework Statement I understand how to find the resonant frequency of a closed pipe but when the thickness of the walls varies, the resonant frequency varies. Is there a formula that i can use to find the resonant frequency of a closed pipe given the length, temperature, speed of sound and...

Please anyone explain that why frequency is more fundamental than wavelength inspire wavelength and frequency depend upon each other again frequency and wave number are also depends upon each other Then why we take the frequency as independent of wave number

I am currently conducting an experiment where I attach a string to a fixed end and run the other end over a pulley (assuming zero friction). A weight is tied to the end to create tension. We currently have length, mass per unit -length and tension, the only issue is measuring the frequency of...

Homework Statement A laser beam is incident at an angle of 30.0° from the vertical onto a solution of corn syrup in water. The beam is refracted to 22.84° from the vertical. (a) What is the index of refraction of the corn syrup solution? I already got the answer of 1.29. (b) Assume that the...

Homework Statement Experimental data for the heat capacity of N2 as a function of temperature are provided. Estimate the frequency of vibration of the N2 molecule. Homework Equations Energy of harmonic oscillator = (n+1/2)ħω C=7/2kB Average molecular energy = C*T But this is an expression...

Hi, For a SoC project I am working on I need to select one cell which is most critical. example, If a bus is going through 1000 stops 1000 times I have mean median mode of delay contribution of that stop compared to the total delay to reach from start to stop point and N (number of times bus...

I don't understand how changing the frequency of a wave effects the energy transferred to electrons following E=hf, but changing the intensity doesnt? Can someone explain it please, some sort of analogy or something?? THANKS!

Homework Statement How can i find the fundamental frequency of a closed piep (measuring cylinder) experimentally/ physicaly. I have done the maths and found the frequency but i want another way to prove this other than simply playing the calculated frequency back at the measuring cylinder. I...

Homework Statement Somebody knows an experiment to measure directly frequency of de Broglie waves?

Homework Statement This is actually part 3 of the question. Part one was to form 7 equations to form a 7x7 matrix, part 2 was to solve it, which I've done. This question is to be done with Matlab, by the way. Part 3: Homework Equations Frequency response = Vout / Vin. The Attempt at a...

Homework Statement I'm having trouble understanding setting up a frequency distribution. I am confident I am doing it right, but the book I'm using differs when calculating width. The problem gives a bunch of numbers representing the number of counties, divisions, or parishes for each of the...

I understand the concepts of photoelectric effect where an electron will be emitted when a photon with sufficient energy collides with it. There are two parts to this question, 1. What happens during the collision? Is the photon absorbed by the photoelectron wholly as energy? 2. If so...

Beam standard atomic clocks work by changing the magnetic state of a cesium atom by applying a microwave frequency that matches the resonant frequency of a cesium atom. What is this resonant frequency of the atom in terms of actual events that occur on the atomic level...

Homework Statement Gravity Waves. Consider a pattern of motion in which fluid elements move at an angle θ to the vertical. Show that for an atmosphere where the Brunt-Vaisala frequency is ωB the elements will oscillate with a frequency ν = N cos θ. Homework Equations , -Brunt Vaisala...

Homework Statement A mass m at the end of a spring oscillates with a frequency of 0.84 Hz . When an additional 730 g mass is added to m, the frequency is 0.65 Hz . Homework Equations f*2pi = w w = (k/m)^1/2 f = (1/2pi)*(k/m)^1/2 The Attempt at a Solution I simply used the third equation...

Just a quick question that I feel should be simple, but I'm unable to come up with a satisfactory answer. A constant signal has an arbitrarily small period (rather, it has no fundamental period), and so it seems to me that this means the frequency of a constant signal grows without bound...

Hi all! I have the following spectrum for a signal force: and this is a zoom in the range of interest: Can I state that this force is capable of exciting the natural frequency of the structure ( in the range 5-30Hz) or the force amplitude in this range is too low compared to the peak...

Homework Statement A research apparatus called a centrifuge undergoes a centripetal acceleration with a magnitude of 3.3x10^6m/s^2. The centrifuge has a radius of 8.4cm. Calculate the frequency of the centrifuge in hertz and in revolutions per minute. Ac=3.3x10^6,/s^2 r=0.084m Homework...

I got question in exam, 1) How to control hardness of X-ray? 2) why low frequency of x-ray is used for investigating tissue?? so in 1) what does controlling hardness means?? and in 2) can't we use high frequency of X-ray ?so that it will penetrate more as tissue are poor absorber...

1. Homework Statement Homework Equations KE=½m(ωa)2 The Attempt at a Solution So first I did this: 2.4x10-3= ½ mω2(1.5x10-2)2 To find mω2=21.33 And substitute that into the KE eqn to find the new amplitude, which is 1.30x10-2 But I only did that because that was the only way I could think...