Frequency Definition and 1000 Threads

Homework Statement A cyclist with a bell ringing with a frequency of 659.7 Hz drives towards a wall with a speed of 8.15 ms-1. Just before colliding with the wall the cyclist hears beats, due to the bell itself and the reflection of the sound from the wall. What is the frequency of beats...

Homework Statement Light (plane wave) reflects from the mirror moving along X-axis with speed V. The wave is orthogonal to the mirror (φ=0°). Write the law for frequency change. Homework Equations I know Lorenz transformation for frequency. The Attempt at a Solution All I do not know is how to...

After the recent discussion here about the Sagnac effect** I wanted to see if there is any frequency shift if light is sent from one point on a rotating worldline to another a small distance away. It looks like this cannot happen because ##\gamma=dt/d\tau## is the same at every point on the...

Homework Statement Given a series RLC circuit, with one R, one L, and one C element, and an AC voltage source with variable frequency, find the resonant frequency experimentally given an ammeter and a voltmeter. Homework Equations The current in the circuit when the circuit is in resonance is...

hello, I'm a first year science undergrad, currently learning about mechanics and waves and so on there's this vine that's been going around, which shows someone playing a harp - here is the video in question; I personally find it quite beautiful and fascinating. Apparently the phenomena is...

Hello there.I have a question about how to find the frequency cutoff in a breadboard with oscilloscope,multimeter etc Ok the circuit it simple.Ac voltage source in series with a resistor,which is in series with a capacitor.I am given that in the frequence cutoff the voltage of the capacitor is...

Hello, I am looking at relating two situations under which cyclic energy is applied to a material. Condition 1: A material has been subjected to a force of 1G at 0.1Hz for 47 days. Condition 2: The same material has been subjected to a force of 4.5G at 60Hz for 3600Seconds. Is it possible to...

Homework Statement A black body absorbs all incident electromagnetic radiation, including visible light which has wavelengths from 380nm to 750nm. IR radiation has wavelengths that are so long they are measured in microns. That suggests that visible light has a higher frequency than IR, and...

Homework Statement Two pipes, Identical in length and closed at one end are producing notes. You are very, very annoyed because the notes are creating an audible beat frequency of 20Hz. If one pipe is producing a note at 10Hz and the temperature is 15C (which correlates to a speed of sound of...

Does anyone have an explanation for these? youtube is filled with videos about them and as many could be fun tricks played by trolls many are also real confirmed in many news media articles heard by witnesses. for example I have heard some physicists explaining them as electromagnetic waves...

Homework Statement (a) Show the relation between frequency received and emitted (b) Find the proper area of sphere (c) Find ratio of fluxes Homework EquationsThe Attempt at a Solution Part (a) Metric is ##ds^2 = -c^2dt^2 + a(t)^2 \left( \frac{dr^2}{1-kr^2}+ r^2(d\theta^2 + \sin^2\theta)...

Hi Friends! Please tell me if the question below is valid? "If the frequency of the source is changed from f to 2f ,keeping amplitude same,then total energy is changed by what amount?" What I conclude is"We can think it in two ways: 1 In classical sense,where I could not find any...

Hello As I read all the above links of Wikipedia about HEMT I have many problems to know better about these kinds of transistor.could you introduce me a good tutorial about HEMT transistors? Thanks

Homework Statement The schwarzschild metric is given by ##ds^2 = -Ac^2 dt^2 + \frac{1}{A} dr^2 + r^2\left( d\theta^2 + sin^2\theta d\phi^2 \right)##. A particle is orbiting in circular motion at radius ##r##. (a) Find the frequency of photon at infinity ##\omega_{\infty}## in terms of when it...

This is a soft question but I think it's a real fact.The Frequency domain has made revolution in the field of Mathematics,Physics,Digital Signal and image Processing etc. Some of concepts which are very difficult to analyse in spatial or time domain can be very easily understood in the frequency...

Homework Statement Determine the center frequency and bandwidth of the bandpass filter. Homework Equations center frequency of bandpass filter = ωc occurs when the magnitude of H = 1 H = V0/Vs Center frequency occurs when Im(Z) = 0 Zc = 1/(jωC) = 1/s ZL = jωL ZR = R I don't know a formula...

Are the angular frequency in electromagnetic waves and frequency of a photon characterise the same physical quantity? I know that these come under two different theory, but I want to know whether these names (angular frequency of em wave and frequency of photon) mean the same physical quantity...

Ive read other threads on here about this and am still slightly confused about it. I did a little experiment; and I am hoping someone can help shed some light on the results. The experiment: 1. Create a system: modeled after a simple spring-mass-damper with mass=1 damping zeta=.1, natural...

hello all.glad to be here! please in the attached document, column 5 and 6 which represents the differential and cumulative frequency distributions were obtained using equations (5) and (6). I'll be mighty grateful if anyone can give me a step by step breakdown of how it was done?? Many thanks...

I apologize in advance for not being physics savy. My question stems from my interest in loudspeaker behavior, but I think I need to clear up some more basic physics. I'm trying to understand what determines the Quality factor of an oscilator/resonator. Given 2 system's with identical spring...

Hi, as I was reading on generators I noticed that apart from the homopolar machine(faraday disc) all other generators are basically AC , or if they are DC then the very current generating loop or part involves changing and time varying currents. They usually have poles on the rotor or stator...

Homework Statement The potential energy of a particle of mass m near the position of equilibrium is given by U=U0sin2(αx) where U0 and α are constants. Find the frequency of the small oscillations about the position of equilibrium. Homework Equations Work energy equation...

Homework Statement *(Problems attached as images)* For first problem: ##\cfrac{|V_2|}{|V_1|} = \cfrac{1}{\sqrt{4+(\omega RC)^2}}## For second problem: ##\cfrac{|V_2|}{|V_1|} = \cfrac{\sqrt{1+(\omega RC)^2}}{\sqrt{4 + (\omega RC)^2}}## I have to calculate half power frequency for both...

I was hoping someone could tell me the phonon frequency of the electrons for YBCO with hole doping of about .2 and a critical temperature of around 75-70°K at about 70°K. An answer in Hz would be preferred, or failing that, in cm-1 with the wave speed. Also, might the Kohn anomaly influence the...

I have been studying the "fallen" photon experiment, in which the frequency of a photon changes as it falls through a height H. f'=f_0(1+\frac{gH}{c^2}) It is often stated that this is a huge factor in the application of GPS. However, I do not understand why. I understand that the photon will...

how can we relate innermost stable circular orbits, keplerian, epicyclic, frame dragging precession frequency with dipole moment.

Homework Statement I am given a frequency value of 95 GHz (9.5x10^10 Hz), C= 25 F, L=1.12x10^(-25) H. The question is to find the uncertainties in frequency by taking account of inductor being 5% accurate & capacitor being 8% accurate. Homework Equations I believe this is the correct formula...

I recently had a lab in physics class that I was a little confused about. I posted a picture of a couple parts of the lab including the instructions and a couple of questions. I also highlighted a few things that confused me. In the instructions it said that all objects vibrate at a set of...

I've read that natural frequency conveyors are very efficient because the drive only compensates for the amplitude that's lost in the elastic supports. Could you please explain how is this different from working at resonant frequency which is so dangerous? P.S. What kind of analysis should I...

Hi, I hope somebody can help me.I'm stuck in this problem..I want to make sure I made it right before sending to the teacher.Thank you very much 1. Homework Statement An 80.0 kg student sits down in his 920 kg car, and his weight causes the causes the car's springs to sink an additional 4.0 x...

Homework Statement Consider a human leg to be a rod of uniform density pivoting about one end. What will the frequency of oscillation be for a leg with a length of 0.82 meters?Homework Equations I believe we need the imagine the leg as a rod, so the moment of inertia would be = 1/3 m L2 The...

From the equation for Z from this website...

I checked some common commercial high-quality lab function generators and they seem to provide frequency output upto 50 Mhz (not a big deal), but with resolution of 1 uHz ! That means, they can generate signal with 50000000 Hz and also with 50000000.000001 Hz ?? That would equate to time-period...

Homework Statement If I attach a spring to the ceiling, then hang a weight on the spring, the spring extends by 1.19 meters, comes to rest for an instant, and then begins oscillating. The mass of the weight is 6.6 kg. What is the oscillation frequency of the block's oscillations. Homework...

Homework Statement A runner is running with speed V along the straight line connecting two identical speakers. Both speakers are playing a tone of the same frequency f. a)What is the beat frequency that the runner hears? b)If the standing wave forms between two speakers, how frequently will the...

I'm considering two types of vibrating feeders, brute force and natural frequency. Can you tell me how natural frequency conveyor works? What kind of design should I choose to transfer light materials? What If I want to use an upwards angle, how do I determine that upward going path of...

Hi all, I‘m a recent member in this forum, very glad I found it. I am interested in light sensing and would like to know if there is any sort of light sensor whose response is manifested and measurable as an emmisson frequency similar to the frequency which is receiving or sensing. I am...

1. A sound wave of the form s = sm cos(kx - ωt + φ) travels at 345 m/s through air in a long horizontal tube. At one instant, air molecule A at x = 2.00 m is at its maximum positive displacement of 6.30 nm and air molecule B at x = 2.09 m is at a positive displacement of 2.40 nm. All the...

Has this been accurately measured yet? Google searches yield results for H 1s-2s and H 1s-3s transitions but not 1s-4s.

Hi all, I am trying to obtain an empirical equation/model having 2 inputs (frequency and S11) and one output (a physical parameter) I have done various simulations using CST of the System and now I am trying to relate S11 and frequency to a physical parameter. Any suggestions of how I should go...

This is not a homework question per se, but rather something I have come across during a homework project. Using Audacity, I recorded a few different instruments playing the same notes (investigating timbre). I noticed that (using a steel string acoustic guitar) the first harmonic at 131 Hz...

From textbook: "In much of the world (Europe, Australia, Asia) the rms voltage is 240 V, so the peak voltage is 340 V. The line voltage can vary, depending on the total load; the frequency of 60 Hz or 50 Hz, however, remains extremely steady" Why is it so important to keep it steady? what...

Homework Statement NOTE: Image uploaded with thread shows problem in clearest possible form. V = (45v)sin(80[pi] t) Resistors 1 and 2 = 50 Ohms Inductor 1 = 20 mH Inductor 2 = 2.5 mH Capacitor = 50 uF a) Find the power dissipated by each resistor. b) At what frequency will both resistors...

Homework Statement The current in a series circuit of R=5 ohms and L=30 mH lags the applied voltage by 80 degrees. Determine the source frequency and impedance. (Ans: Z=5+j28.4 , f=150.4 Hz) Homework EquationsThe Attempt at a Solution Current in the inductor, IL = Vm/wL*sin(wt-80) Current...

Homework Statement Please see attachment for diagram. The two boats are coherent sources of sound waves (phase difference ## \phi##) - i.e it's a double slit problem. Prove the formula given for ## y_{max}##. Suppose the whale is 20m long. How large should the sonar frequency ##f## be so that...

I've always just accepted that as you scale down a mechanical system the frequency and Q factor both increase. For example, this Wikipedia page simply says that "Small bells ring at higher frequencies than large bells". But for a driven damped harmonic oscillator, what is the exact relationship...

I am looking to find the resonant frequency of the amplified tuner circuit below The equation I have attempted to use is the f = 1/2*pi*√LC With the values for the inductance capacitance being 22pF and 47mH as I believe this is the tuner part of the circuit? The value I get by inserting these...

Can someone please explain intuitively how the terms “frequency” and “dynamics” are related ? I understand the concept of each of these two individually, but I am having some difficulty visualizing what high-frequency dynamics mean. I understand the concept of how time and frequency domains...

Homework Statement A spring is attached to the ceiling, a pulley is attached to the other end of the spring, a string is suspended over the pulley, and a mass attached to the free end of this string. The system oscillates vertically. Can someone PLEASE help me derive this equation for natural...

I've been a bit lost figuring out what damper I should be using for the front suspension I am designing. Right now I'm running a wheel rate of 60 lbf/in at the front with a ride frequency of 1.2254 Hz. The front is also supporting a sprung mass of 391.68 lbf. Comfort is the end requirement of...