Posted: 4/2/2014 8:52:21 PM EDT
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so im calculating wavelength of frequency.
100.2 MHz, Wavelength= Speed of light (3x10^8) / V v is frequency. frequency given is 100.2 Mhz. 1 MHz is = 10^6 according to my text book. but 1MHz is 10^6 of what? |
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Quoted:
Oh. well i wish the text book wouldove added "Hz". damnit. so for 1070Khz, devide by 1000 to get Hz, get 10.7hz? 3x10^8/1.07x10^7 = Wavelength 28.03738318 Meters right? Quoted:
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1Mhz = 1*10^6 Hz = 1,000,000 Hz Oh. well i wish the text book wouldove added "Hz". damnit. so for 1070Khz, devide by 1000 to get Hz, get 10.7hz? 3x10^8/1.07x10^7 = Wavelength 28.03738318 Meters right? If the formula you provided is correct, your math is correct |
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Quoted:
so im calculating wavelength of frequency. 100.2 MHz, Wavelength= Speed of light (3x10^8) / V v is frequency. frequency given is 100.2 Mhz. 1 MHz is = 10^6 according to my text book. but 1MHz is 10^6 of what? Wave length = 1/f x 300000000- wavelength in meters 1/100200000 x 300000000= 2.994 meters |
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If the formula you provided is correct, your math is correct Quoted:
Quoted:
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1Mhz = 1*10^6 Hz = 1,000,000 Hz Oh. well i wish the text book wouldove added "Hz". damnit. so for 1070Khz, devide by 1000 to get Hz, get 10.7hz? 3x10^8/1.07x10^7 = Wavelength 28.03738318 Meters right? If the formula you provided is correct, your math is correct 
for this purpose. speed of light is rounded to 3.00x10^8 |
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Quoted:
Oh. well i wish the text book wouldove added "Hz". damnit. so for 1070Khz, devide by 1000 to get Hz, get 10.7hz? 3x10^8/1.07x10^7 = Wavelength 28.03738318 Meters right? Quoted:
Quoted:
1Mhz = 1*10^6 Hz = 1,000,000 Hz Oh. well i wish the text book wouldove added "Hz". damnit. so for 1070Khz, devide by 1000 to get Hz, get 10.7hz? 3x10^8/1.07x10^7 = Wavelength 28.03738318 Meters right? Wrong way. A KHz is 1000 Hz, a MHz 1,000,000 Hz, a GHz is 1,000,000,000 Hz. The faster the frequency the shorter the wave length. This is true regardless of whether you are concerned with sound, light/EMF, or water waves in the ocean. Edit. Oops. I read that wrong. |
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Quoted:
Oh. well i wish the text book wouldove added "Hz". damnit. so for 1070Khz, devide by 1000 to get Hz, get 10.7hz? 3x10^8/1.07x10^7 = Wavelength 28.03738318 Meters right? Quoted:
Quoted:
1Mhz = 1*10^6 Hz = 1,000,000 Hz Oh. well i wish the text book wouldove added "Hz". damnit. so for 1070Khz, devide by 1000 to get Hz, get 10.7hz? 3x10^8/1.07x10^7 = Wavelength 28.03738318 Meters right? 1070Khz = 1070 * 10^3 Hz = 1,070,000Hz. 1,070,000Hz = 1.07*10^6Hz = 1.07Mhz The prefixes seem to be throwing you off, but they're not tricky at all once you understand what you're dealing with. K = kilo = 10^3. M = mega = 10^6. G = giga = 10^9. If you're dealing with SI units (in your case, the speed of light in meters per second) then everything else in your math needs to be in SI units as well. That means using Hz, and not Khz, Mhz, or Ghz. Notice though that if you divide (for example) KHz by KHz, you get the exact same result as dividing Hz by Hz or Mhz by Mhz, since the prefixes cancel out. |
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Quoted: Okay . Just studied Mega and Kilo hertz so I'm given. 1070KHz 1070Khz = 1070x10^6 Hz. right? to find the wavelength of 1070 KHz. i convert it to Hz. so 1070KHz is 1.070x10^6 Hz correct? divide the speed of light 3x10^8 by 1.070x10^6 and i get 280.4 M |
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Quoted: Okay . Just studied Mega and Kilo hertz so I'm given. 1070KHz 1070Khz = 1070x10^6 Hz. right? to find the wavelength of 1070 KHz. i convert it to Hz. so 1070KHz is 1.070x10^6 Hz correct? divide the speed of light 3x10^8 by 1.070x10^6 and i get 280.4 M 3x10^8 (m/sec) / 1.070x10^6 (cycles/sec) = about 300 m (cycles drops out because it's not really a unit; it's 1). yeah, you're answer sounds right only with a lower case m. Always keep track of your units. It's common to just use: 300/freq (MHz) = wavelength (m) |
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1/f gives time for one cycle in seconds. Times 300000000 gives distance light travels during one cycle gives wavelength. 2.994 meters.
If the frequency was an even 100 Mhz the wavelength would be an even 3 meters. I've got experience working with slotted lines measuring VSWR. I'd call it 3 meters and say close enough. |
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Quoted:
Oh. well i wish the text book wouldove added "Hz". damnit. so for 1070Khz, devide by 1000 to get Hz, get 10.7hz? 3x10^8/1.07x10^7 = Wavelength 28.03738318 Meters right? Quoted:
Quoted:
1Mhz = 1*10^6 Hz = 1,000,000 Hz Oh. well i wish the text book wouldove added "Hz". damnit. so for 1070Khz, devide by 1000 to get Hz, get 10.7hz? 3x10^8/1.07x10^7 = Wavelength 28.03738318 Meters right? 1070Kh x 1000=1,070,000 Hz 280 meters |
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Always keep the units with the math and you won't have problems. Hz = cycles per second. 1/Hz = seconds per cycle Speed of light in meters per second divided by frequency in cycles per second leaves meters per cycle, if that helps you understand it. Sounds correct. |
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Memorize This:
c=f • L c= speed of light (meters per second results in meter wavelengths, using feet per second results in wavelegth in feet) c~= approx 300x106 or 3x108 meters/second f=Frequency in cycles per second (Hertz/Hz) L=Wavelength in units matching speed of light (typically meters) (L = greek letter small Lambda), Capital Lambda is the "Spartan symbol" |