What frequency does the person hear coming from the stationary car?
Q. A person is running toward a stationary car at a speed of 6.0 m/s and another car is moving away at a speed of 25 m/s. The horn in each car is producing a sound with a frequency of 920 Hz. a) What frequency does the person hear coming from the stationary car? b) What frequency does the person hear coming from the moving car? c) What beat frequency does the person hear? d) The stationary car starts moving towards the person at a speed of 10.0 m/s. What is the new beat frequency heard by the person?
Asked by Bill T - Wed Jun 27 03:25:57 2007 - - 3 Answers - 1 Comments

A. F=the frequency that the person hear. f=the car stationary frequency if the person is in front of the stationary car: F=(V(sound)+v(person)/V(s ound)-v(car))f and if the person is behind the car: F=(V(sound)-V(person)/V(s ound)+v(car))f Just put the numbers in these formulas
Answered by Nb - Wed Jun 27 03:41:36 2007

What does the corner frequency for a speaker crossover network represent, and how do you calculate it?
Q. I built a simple crossover network using just an inductor as a lowpass filter an just a capacitor as a high-pass filter for an electronics class. (Then hooked up to a woofer and a tweeter) I have all the data pertaining to the circuit, including graphs of the transfer function versus frequency, but now I need to calculate the corner frequency observed in the network we built, then calculate the values of the capacitor and inductor needed to make a crossover network with a corner frequency of 1 kHz for both speakers. Problem is, I have absolutely no idea what a "corner frequency" is, so any help would be appreciated.
Asked by dsama86 - Fri Mar 10 00:10:13 2006 - - 1 Answers - 0 Comments

A. On a low pass filter, the corner frequency is the frequency at which the output power drops 3dB from the dc point. This corresponds to the point where the output voltage decreases by 30% (or, more accurately, where it drops to 1/sqrt(2) of the dc value). So, if you already have measured the output voltage over frequency (with a constant amplitude input voltage), then just find the frequency at which the output voltage drops 30%. Do the same for your high pass, only this time find the point at which the voltage is 30% less than the high frequency 'flat' portion. If you designed your speaker network correctly, both the low pass and high pass would have the same crossover frequency.
Answered by seasnowsky - Fri Mar 10 19:05:05 2006

What is the frequency of all visible colors?
Q. I need to figure out the wavelength, frequency and energy of red, orange, yellow, green, blue, indigo and violet. I just need to figure out the frequency, then I can figure out the rest but I can't find the frequency of any of the colors.
Asked by mountainair13 - Thu Oct 29 13:21:05 2009 - - 2 Answers - 0 Comments

A. Google found your answer for future reference.
Answered by Jerk - Thu Oct 29 13:30:18 2009

What is the highest frequency of light, and why?
Q. E=hf=mc^2. As the light gets higher in frequency, its energy increases, and its wave length decreases. Is there a limit on this? 1. Photon has so much energy that it turns anything it encounters into mini black hole, thus making observation impossible. If true, what frequency is this? This is related to my other question; does increase in energy necessarily mean increase in gravitational mass, thus resulting in mini black hole for super energetic particles? 2. Wavelength becomes less than planck (or planck bar), at which point what happens? Is planck (or bar) the limit on the wavelength of light? Why? In any case, what is the highest frequency light that one can observe, and why? Does the photon itself create a black hole or does the… [cont.]
Asked by Mik K - Sun Jun 10 19:50:30 2007 - - 1 Answers - 0 Comments

A. The highest possible frequency of light is the wavelength corresponding to the Planck length. More than that much energy localized in that small a space would open a black hole (be inside its own Schwarzschld radius). l_p = sqrt[(hG)/2(pi)c^3]
Answered by Uncle Al - Sun Jun 10 19:58:06 2007

What's the difference between frequency and luminosity if frequency is indicative of energy? What's the differ?
Q. What's the difference between frequency and luminosity if frequency is indicative of energy? What's the difference between frequency and energy? What has energy that doesn't exhibit wave like properties?
Asked by aondrea S - Sun Feb 14 15:42:55 2010 - - 1 Answers - 0 Comments

A. The difference between frequency and luminosity is based on what you mean by energy. For light, the frequency defines the energy per photon; the luminosity is the total energy emitted (which then depends on the energy per photon multiplied by the number of photons emitted).
Answered by Euan R - Thu Feb 18 09:54:47 2010

What is the maximum frequency for which the penny just barely remains in place for the full cycle in Hz?
Q. A penny rides on top of a piston as it undergoes vertical simple harmonic motion with an amplitude of 4.0 cm. If the frequency is low, the penny rides up and down without difficulty. If the frequency is steadily increased, there comes a point at which the penny leaves the surface. What is the maximum frequency for which the penny just barely remains in place for the full cycle in Hz?
Asked by gbutterfly339 - Thu Nov 8 18:24:38 2007 - - 1 Answers - 0 Comments

A. If the acceleration of the piston a exceeds g the penny will leave the surface. a = omega^2*amplitude omega = sqrt(g/0.04) f = omega/(2*pi)
Answered by kirchwey - Thu Nov 8 19:25:34 2007

What is the fundamental frequency of the original tube?
Q. A tube, open at only one end, is cut into two shorter (non-equal) lengths. The piece open at both ends has a fundamental frequency of 624 Hz, while the piece open only at one end has a fundamental frequency of 773 Hz. What is the fundamental frequency of the original tube?
Asked by Bill T - Tue Jun 26 03:31:09 2007 - - 2 Answers - 0 Comments

A. 624=v/2l 773=v/4L orignal lenght=L+l v=340m/s
Answered by tarundeep300 - Tue Jun 26 03:39:33 2007

What is its frequency when an open-open tube is filled with 0 degrees air?
Q. The fundamental frequency of an open-open tube is 1500 Hz when the tube is filled with 0 degrees helium. What is its frequency when filled with 0 degrees air?
Asked by Star - Sat Mar 6 18:44:47 2010 - - 2 Answers - 0 Comments

A. 512Hz
Answered by zoidz - Mon Mar 8 01:30:12 2010

How does natural frequency relate to cars and bumpy roads?
Q. My dad and I were disagreeing about this. We know that sometimes it is better to go over a bumpy road really fast, but he was saying because that was close to the natural frequency of the springs between the car body and the wheels. I was saying that you want to be at a different speed from what would be natural frequency, because that would actually cause the most motion. Also, do shock absorbers affect this?
Asked by WearingPink - Wed Apr 8 11:17:14 2009 - - 1 Answers - 0 Comments

A. You're correct. You don't want to tune the excitation to the system. If it were true that the result would be a minimum, there would be a sweet-spot speed of minimum jounce above which it would increase. This doesn't happen. Above the resonant frequency, the system acts like a low-pass filter and the amplitude decreases as speed increases. Anyway you can tell that by comparing the washboard frequency to the suspension frequency f0. Usually f0 is around 1 Hz while you're skittering over the bumps at more like 5 Hz or so. Measure f0 by the jump-on-the-bumper test, then drive at a bump rate near f0 and you'll know it! Shocks certainly affect this. They should broaden the resonant frequency peak but reduce its amplitude.
Answered by kirchwey - Wed Apr 8 12:58:42 2009

how do you calculate relative frequency from a frequency distribution table?
Q. Also, is the cumulative frequency just all the frequencies added up? Or is there some equation to it?
Asked by lostprophetslove - Thu Nov 15 14:21:27 2007 - - 2 Answers - 0 Comments

A. frequency is the number of observations of a given type. relative frequency is the number of observations of a given type divided by the total number of observations. for example, if you are looking at the color of cars passing through an intersection in a time unit and observe { green, blue, red, red, white, black, green, red, black, black, black, red, blue} there are 13 observations the frequency of green cars is: 2 the frequency of blue cars is: 2 the frequency of red cars is: 4 the frequency of white cars is: 1 the frequency of black cars is: 4 the relative frequency of green cars is: 2/13 the relative frequency of blue cars is: 2/13 the relative frequency of red cars is: 4/13 the relative frequency of white cars is: 1/13 the… [cont.]
Answered by Merlyn - Fri Nov 16 18:16:38 2007

What is the frequency of heterozygous carriers?
Q. The frequency of an allele in a large randomly mating population is 0.2. What is the frequency of heterozygous carriers?
Asked by pinkpanther - Tue Jul 21 18:26:52 2009 - - 1 Answers - 0 Comments

A. this may be your answer
Answered by aboodee - Tue Jul 21 18:36:26 2009

How do you use frequency formula in Excel?
Q. I have a spread sheet with 1094 rows that contain values from 1-9. I need to determine the frequency of each digit in data but I can't figure out how to use the frequency function. Can anyone please explain. Thank you.
Asked by PJ - Wed Jun 3 02:10:52 2009 - - 2 Answers - 0 Comments

A. A step by step example of how to use the frequency function: 1. Identify a range of data on which you want to perform your frequency analysis. (C5:C16) 2. Create a vertical range of cells containing the upper bandings with which you wish to group your data (i.e. 0-12, 13-16, 17-20, 21-24) 3. Highlight a vertical range of cells in which you wish the analysis to be reported (F5:F9). Note that by extending this output range by one extra cell, you can capture all values above the maximum banding (i.e. over 24). 4. With the whole output range highlighted, type the formula. = frequency(C5:C16, E5:E8) 5. Do not press enter. This is an array function and therefore requires you to use the alternative key strokes of + + … [cont.]
Answered by TURLOCK0000000000 - Wed Jun 3 02:17:32 2009

What's the difference between frequency and hertz?
Q. I believe frequency is the number of crests in 1 second. Hertz is a measure of frequency. 1 wave per second is equal to 1 hertz. But this just seems to me like hertz is just another name for frequency? Does hertz measure crests and troughs?
Asked by KnottedBrain - Wed Aug 29 01:19:04 2007 - - 13 Answers - 0 Comments

A. hertz is the unit of frequency.
Answered by bilbo - Wed Aug 29 01:23:23 2007

What is the expected frequency of pattern-bald males and pattern bald females in the population?
Q. Pattern baldness in humans is an autosomal, sex-influenced trait; it is dominant in males and recessive in females. A male with at least one copy of the pattern baldness (PB) is bald; however, two copies of this allele must be present for a female to be bald. The frequency of the PB allele in a particular population has been estimated to be 0.3. Assuming random mating, what is the expected frequency of pattern-bald males and pattern bald females in the population?
Asked by pinkpanther - Tue Jul 21 18:10:56 2009 - - 1 Answers - 0 Comments

A. To make simple, b is allele for baldness and B is for normal. p(B) = 0.7 q(b) = 0.3 According to Hardy-Weinberg: (p + q)^2 = p^2 + 2pq + q^2 So, the frequency of p^2(BB) = (0.7)^2 = 0.49 (normal males and females) 2pq(Bb) = 2 x 0.7 x 0.3 = 0.42 (bald males or normal females) q^2(bb) = (0.3)^2 = 0.09 (bald males and females) Since in males, b is dominant over B; and in females B is dominant over b, then the expected frequency of - pattern-bald males = 1/2 (sex) x (0.42 + 0.09) (baldness) = 0.255 - pattern-bald females = 1/2 (sex) x (0.09) (baldness) = 0.045 and - normal males = 1/2 x 0.49 = 0.245 - normal females = 1/2 x (0.49 + 0.42) = 0.455
Answered by Abu - Wed Jul 22 22:47:25 2009

What frequency band are the teacher wireless microphone on?
Q. I am speaking of the classroom wireless microphone which usually have a wrap around neck piece so they don't have to yell loud, just talk into the microphone. What frequency band is this on? Thx!
Asked by ostyman09 - Tue Sep 11 21:23:27 2007 - - 2 Answers - 0 Comments

A. Some of the frequencies I've listed below. You would have to search, as different systems use different bands, depending how expensive a system it is, how old it is, etc. 169-210 MHz.. (Specifically, 169.445, 169.505, 170.245, 170.305, 171.045, 171.105, 171.845 and 171.905) 518-578 MHz 578-608 614-698 740-814 (try 779-788 / 797-806) Good Luck
Answered by Jeremy B - Wed Sep 12 07:40:25 2007

What is the fundamental frequency and wave speed?
Q. Standing waves on a 1.9-m-long string that is fixed at both ends are seen at successive frequencies of 24Hz and 48Hz. What is the fundamental frequency? What is the wave speed?
Asked by ginger_jj - Mon Apr 21 17:36:50 2008 - - 1 Answers - 0 Comments

A. Notice that 24 Hz is exactly double the frequency of 48 Hz. We know that for a string fixed at both ends, f= mv/2L, where f= frequency m= mth mode v= velocity of STRING L= length of string Thus, the fundamental frequency of the string must be 24 Hz. For fundamental frequency where m=1, we can solve for v: f= mv/2L 24 = (1)v/2(1.9) 24 = v/3.8 91.2m/s = v [Answers: see above]
Answered by /\/ ? - Mon Apr 21 18:29:56 2008

What is the conversion for nanometers to frequency?
Q. What is the conversion for nanometers to frequency? Convert a wavelength of 400 nm to frequency in hertz. What color is this light? Laser pointers emit light waves with a wavelength of 670 nm. What is the frequency of that light?
Asked by darkshadow07054 - Sun Apr 12 07:52:29 2009 - - 1 Answers - 1 Comments

A. c = frequency * wavelength c = 3 x 10^8 frequency = c / wavelength = 3 x 10^8 / 670 x 10^-9 Solve this you will get the answer. It is the wavelength of red light.
Answered by Giles - Sun Apr 12 08:00:47 2009

What frequency range is used for Wireless communications?
Q. I think the spectrum is divided into several frequencies. Some of it is visible light and other things like UV, IR and X rays. What frequency range do the 'radio waves' occupy? And what frequencies are used for: GSM communications, walkie talkie, satellite communications?
Asked by Mk - Wed Oct 22 11:21:12 2008 - - 1 Answers - 0 Comments

A. See ( for the current US Frequency Allocation for Radio Spectrum, which runs from 3 kHz to 300 GHz. The classification of electromagnetic spectrum is as follow (starting from lowest frequency to highest): 1. Radio 2. Microwave 3. Infrared 4. Visible 5. UV 6. X-Ray 7. Gamma Ray ( It is technical possible to use any of the above spectrum for wireless communications, i.e. it is not limited to just radio or microwave. GSM is as follow (note that only EU countries specify these bands should be GSM while all other countries may use any other type of modulation and multiple access method such as CDMA, AMPS, iDEN, etc.): 1. USA / North America = 850 MHz, 1900 MHz 2. Rest-of-the-World (ROW) = 900 MHz, 1800 MHz Walkie Talkie can occupy… [cont.]
Answered by Tat - Wed Oct 22 12:32:03 2008

What is the frequency of the tuning fork?
Q. Two out-of-tune flutes play the same note. One produces a tone that has a frequency of 241 Hz, while the other produces 286 Hz. When a tuning fork is sounded together with the 241-Hz tone, a beat frequency of 24.0 Hz is produced. When the same tuning fork is sounded together with the 286-Hz tone, a beat frequency of 21.0 Hz is produced. What is the frequency of the tuning fork?
Asked by Ashmeg - Fri Feb 12 11:53:59 2010 - - 1 Answers - 0 Comments

A. The 241 hz produces a 24 hz beat with the tuning fork..so the fork is either 241 + 24= 265 or 241 - 24 = 217. However with the 286hz the21 hz beat means either the tuning fork is 286-21 = 265 or 286+24 =310 Looking a t both cases the tuning fork is 265Hz
Answered by DH - Sun Feb 14 02:25:35 2010

How to hook up a frequency meter for a generator?
Q. I've got a generator, and I need to set the frequency, so I bought a cheap frequency meter on ebay. It's a Wacline N20394A analog panel meter apparently off an old Kurz & Root generator. It measures 55-65 Hz. It has two terminals on the back, one is marked with a + sign, the other is unmarked. There is a little spring like wire that bridges the two terminals in the back. I have no instructions, diagrams, etc, and have no idea how to hook up this meter. Anyone out there have any ideas? Ed.
Asked by Ed A - Sat Jul 14 13:25:54 2007 - - 2 Answers - 0 Comments

A. I think that jesem47 is correct if you have the complete meter. Sometimes panel meters that are marked as indicating various things are simply 0-1mA dc movements that must be connected to some kind of signal processing circuit that converts the measured quantity to a 0-1mA signal. If that is the case, applying 24 VAC through a fuse larger than 1mA could fry the meter. Of course, if you don't have the complete meter, you probably don't care what happens to it. If you want to check it out completely without frying it, start with a series resistor of sufficient resistance to limit the current to 1mA with what ever voltage you apply for test purposes. You should probably remove the wire from the back. It may be a shorting wire that was… [cont.]
Answered by Retired EE - Sat Jul 14 16:46:31 2007