# What is Hertz: Definition and 38 Discussions

The hertz (symbol: Hz) is the derived unit of frequency in the International System of Units (SI) and is defined as one cycle per second. It is named after Heinrich Rudolf Hertz (1857-1894), the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz are commonly expressed in multiples: kilohertz (103 Hz, kHz), megahertz (106 Hz, MHz), gigahertz (109 Hz, GHz), terahertz (1012 Hz, THz), petahertz (1015 Hz, PHz), exahertz (1018 Hz, EHz), and zettahertz (1021 Hz, ZHz).
Some of the unit's most common uses are in the description of sine waves and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation of energy, via the photon energy equation (E=hν), with one hertz equivalent to h joules.

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1. ### How to Convert Diffusion Rate to Hertz?

How to Convert Diffusion Rate to Hertz - Hi, new here. Does anyone know if it is possible to convert the molecular diffusion rate to a frequency in hertz?
2. ### Engineering Hertz contact problems of three cylinders

Greetings i´m trying to find the Force applied by the upper roller to calculate the contact surface. Here is indeed my solution 2*FR1* cos31,38=F=1500N FR1=878,57N (which is wrong the correct solution says 818,1N) FR1 is the force normal to the surface of contact. any help would highly...
3. ### Hertzian contact pressure & shear stress

Hello, I am trying to get some intuition about the direction of the shear stress caused by the Hertz contact pressure. Once I exert some pressure downwards on a spherical object the direction of the Hertz pressure will be upwards. However, this case some shear stress to exist, but I can't see...
4. ### Hertz contact stress with prescribed displacement

Hi, one can easily find formulas for Hertz contact stress in various cases (two spheres, two cylinders and so on) when force is applied to one of the bodies. But how to get the equivalents of those formulas when prescribed displacement is used instead of stress ? For example, I’ve found this...
5. ### Does Heinrich Hertz' apparatus include a proper antenna?

How close to "antenna" was the metal barbell thing which was part of Heinrich Hertz' apparatus? Did he know in theory how to build a radio but just didn't have the right components to do it? I know someone around that time referred to the problem of radio in terms of needing proper sustained...
6. ### B Is a Spark Necessary for the Production of EM Waves in the Hertz Experiment?

Hello, so I was reading bout the Hertz experiment in different text and they always say something about the Spark causing accelerated electric charge. So I was wondering, is the spark necessarily for the production of EM waves? If yes, why? Because as I recall, applying an ac voltage should...
7. ### I Hertz Experiment: Original Paper on Photoelectric Effect

Can anyone share original paper of Hertz experiment on photoelectric effect.
8. ### I How does the Franck-Hertz experiment demonstrate energy quantization in atoms?

In the experiment, it is observed that the minimum value of anode current occurs periodically and its period multiplied with e is known as excitation potential energy. I don't see the link between this periodicity and quantisation of energy levels of atom. Could anyone please make this clear?
9. ### B Question in Franck and Hertz Experiment

My book gives the following graph for current vs accelerating potential for Franck and Hertz experiment (used to prove existence of discrete energy levels in atoms) using Mercury vapours in the tube: The book then writes: "Actually, atoms have more than one excitation potential and also an...
10. ### How can i generate an 8 hertz AC current from 60 hz AC

Hello there. i would like to request some help please in the design of my meditation pyramid. If you can help me out i'd be greatly appreciative thank you. I would like to set up an 8 hertz oscillating magnetic cycle around the pyramid. Why? because i wish to entrain higher alpha brainwave...
11. ### What is an intuitive definition of Hertz?

So I have been told that I have a 240V-250V supply at 50Hz... What does 50Hz mean and please give analogy if possible, I am new to this stuff Thank you in advance
12. ### How many hertz can kill flying house insects?

How many hertz can kill a flying house insects...
13. ### MATLAB Analyzing Franck Hertz Graph on Excel/Matlab

Hello, How can I determine when the current is starting rise? What methods should I use to do so? on excel or matlab. I've attached an image of my graph below Thanks a million
14. ### Help Needed with Franck Hertz Oscillation Lab Report Analysis

Hello, I'm writing my lab report for my Franck Hertz oscillation and I seem to be stuck on analysis part where I have to perform auto-correlations. Could anyone please guide me through steps 2-4 on excel? I absolute have no idea what the steps 2-4 is asking me to do. For instance, for step...
15. ### Help with Hertz and BPS in communication channels

Hi, I am researching communication channels such as UTP, coax etc and I keep seeing them referred to with either M/k/G bps and MHz. Am i correct in thinking bps is the data transfer speed and Hz is referring to bandwidth as I am getting confused? Thanks
16. ### Franck hertz experiment problem

Homework Statement a beam of electrons bombards a sample of hydrogen. through what potential difference must the electrons have been accelerated if the first line of balmer series is to be emitted Homework Equations 1/l=R(1/2^2-1/3^2) E=hc/l v=E/Q The Attempt at a Solution...
17. ### Reasons why the Franck Hertz experiment might fail

We conducted the Franck Hertz experiment with mercury vapour and got intervals for the excitation potential of 5.75 and 6.40 V. I know that the intervals should be 4.9 V. The potentials were measured using an oscilloscope at the most convenient scales. I just can't think what may have gone...
18. ### Franck hertz Experiment-Ionization vs Excitation

Franck hertz Experiment--Ionization vs Excitation Homework Statement We performed the Franck-Hertz experiment with neon gas. As we raised the accelerating voltage, the electrons gained enough energy to raise the energy of the neon through inelastic collisions. Those electrons lose some energy...
19. ### Hertz level of solid state matter

Is there a general level of vibration that describes most solid state matter that we can touch? Perhaps in hertz?
20. ### Hertz Fellowship - Prep Tips & Interview Q&A

Hello everyone, I have luckily gotten into the first round of the Hertz fellowship interview. Does anyone have any suggesitons that would help me to prepare? Are there any past Hertz fellows or others who have gotten into the interview? If so, can you guys drill me with similar...
21. ### How did Henrich Hertz measure UHF waves?

I've been reading about the history of the verification of maxwell's theory, and I'm a bit confused how people in those times could measure such high frequencies. I imagined they used instruments that were much more mechanical, and so I'm not sure how they could know or measure things that...
22. ### Why and How, are Computer speeds measured in Hertz?

Hey everyone. I'm beginning my exciting yet very nerve wracking road to a BS in computer science. I'm attending a university in NJ and hope to do well here. I love communications, networking, and all that jazz. Any who, one question has been bothering me. In my studying of computers, and how...
23. ### Hertz Contact Solution of Elastic Theory for Concave to Convex Shapes

For the equation: contact stress = {(1 / (pi[((1-v1^2)/E1)) + ((1-v2^2)/E2))) ^ 0.5} * {((Fn/b) * (Sum (1/pi)))^0.5} Where Sum (1/pi) = [(1/p1) - (1/p2)] for concave shapes in contact with convex shapes Sum (1/pi) approaches 0 as the two radii get closer, however when the two radii...
24. ### Learning about Hertz Vector: A Guide

Can anyone tell me about Hertz vector?..At least it would be enough if anyone can tell me a book where I can learn about it..!
25. ### Franck Hertz experiment - overheated tube

Homework Statement What happens when the tube is (a) overheated or (b) too cool. Homework Equations The Attempt at a Solution I searched on google and almost all said: " If the tube has been overheated, the emission current is small, and maxima and minima can hardly be recognized or...
26. ### Hertz and polarization of EM waves

Hi, I'm having difficulty understanding exactly how the reciever loop detects the EM waves in this experiment and I can't find any definitive information online. My understanding is that since EM waves are transverse, to be absorbed by the receiving electrodes, the length of the molecule chains...
27. ### Hertz Contact Stress for static condition

Hi all, I am designing a set of side guide rollers for a vertical gate. There are four rollers on the gate (two on each side), and the rollers are designed for jamming load condition (they are not loaded most of the time). When jamming happens, one top roller and one bottom roller (on the...
28. ### Calculate the frequency, in hertz (level n = 10 to level n = 5)

Calculate the frequency, in hertz, of the photon that is emitted when a electron falls from level n = 10 to level n = 5 in the H atom. Enter a numeric answer only, no units. I tried asking in other places but ppl are so ambiguous about it. :( please help me. I used rydberg formula...
29. ### Calculate the frequency, in hertz (level n = 10 to level n = 5)

Calculate the frequency, in hertz, of the photon that is emitted when a electron falls from level n = 10 to level n = 5 in the H atom. Enter a numeric answer only, no units. I tried asking in other places but ppl are so ambiguous about it. :( please help me. I used rydberg formula...
30. ### Unwanted Computer Usage: 50Hz Refresh Rate Issue on My Lab Computer - Need Help!

my computer in the lab has been used without my permission by a labmate He told people that he knew about computer OS, he partitioned the computer discs into many rooms. There is a drive room for my Windows XP 2003 Service Park 2. He installed some OS I don't know what to call on the other free...
31. ### Uncovering Heinrich Hertz: The First to Generate EM Waves in a Lab

My notes say that Heinrich Hertz was the first to generate and detect EM waves in the lab. ... Uhhh, this might seem really basic to you guys, but what exactly are EM waves? Because I thought they were any type of wave that appears on the electromagnetic spectrum, including visible light...
32. ### Questions About Franck-Hertz Experiment

I am not sure if this is the right place to post this so sorry if it is wrong. Be that as it may... I have just completed a lab in which we do the Franck-Hertz experiment. I am trying to understand it so I have a couple of questions I hope you can help with. 1) There is an oven into...
33. ### Hertz Contact Stress: Calculating & Comparing Allowable Stress

HI All: Using Hertz contact formula I calculated contact stress for cylinder in contact with cylinderical socket but I don't know to which stress to compare this contact stress.Actally I comapred with material bearing stress & calculated stress was less that bearing stress(got margin of...
34. ### Induction Coils and/or Hertz Experiment

Hi everyone, Just a quick question that was bugging me... If i was asked to draw the voltage output vs time of an induction coil...would it be absolute value sine curve?? Secondly i absolutely don't understand how in Hertz experiment, what the sparks jumping across have anything to do...
35. ### Calculating Frequency and Wavelength of Sound Waves in Water and Air

i really had troubles with solving this problem and it would be greatly appreciated if i can get a full solution, thank you A vibrating 400.0 Hz tuning fork is placed in fresh water. What is the frequency in hertz and the wavelength in metres. a) within the water at 25 C b) when the...
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### Hertz's Radio Wave Experiment: A Comprehensive Study | Resources and References

I am from Portugal and from the school books I could not understand in all his dimension Hertz experiment in which he produced radio waves in laboratory. If you could refer some sites (I have searched a lot) it will be good but even better if you could send me some pages scanned from books...
37. ### Questions about Franck Hertz Experiment: Energy, Mean Free Path, Interactions

I am reading about the Franck Hertz experiment from a text and have some questions about it since I am quite confused... How do electrons interact with mercury and helium atoms? I hope this is not too stupid a question for you guys... What has to be the energy of the electron so that the...
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### Franck Hertz expiriment (maybe you know?)

Franck Hertz expiriment (maybe you know??) in experiment i performed of Franck H I got that the maxima interval are becoming larger as the temprature grows. This is not as it should be by the theore Can anyone answer that ?