Answer:
a). 100.2 MHz (typical frequency for FM radio broadcasting)
The wavelength of a frequency of 100.2 Mhz is 2.99m.
b. 1070 kHz (typical frequency for AM radio broadcasting) (assume four significant figures)
The wavelength of a frequency of 1070 khz is 280.3 m.
c. 835.6 MHz (common frequency used for cell phone communication)
The wavelength of a frequency of 835.6 Mhz is 0.35m.
Explanation:
The wavelength can be determined by the following equation:
(1)
Where c is the speed of light,
is the wavelength and
is the frequency.
Notice that since it is electromagnetic radiation, equation 1 can be used. Remember that light propagates in the form of an electromagnetic wave.
<em>a). 100.2 MHz (typical frequency for FM radio broadcasting)</em>
Then,
can be isolated from equation 1:
(2)
since the value of c is
. It is necessary to express the frequency in units of hertz.
⇒ ![100200000Hz](https://tex.z-dn.net/?f=100200000Hz)
But ![1Hz = s^{-1}](https://tex.z-dn.net/?f=1Hz%20%3D%20s%5E%7B-1%7D)
![\nu = 100200000s^{-1}](https://tex.z-dn.net/?f=%5Cnu%20%3D%20100200000s%5E%7B-1%7D)
Finally, equation 2 can be used:
![\lambda = \frac{3x10^{8}m/s}{100200000s^{-1}}](https://tex.z-dn.net/?f=%5Clambda%20%3D%20%5Cfrac%7B3x10%5E%7B8%7Dm%2Fs%7D%7B100200000s%5E%7B-1%7D%7D)
![\lambda = 2.99 m](https://tex.z-dn.net/?f=%5Clambda%20%3D%202.99%20m)
Hence, the wavelength of a frequency of 100.2 Mhz is 2.99m.
<em>b. 1070 kHz (typical frequency for AM radio broadcasting) (assume four significant figures)</em>
<em> </em>
⇒ ![1070000Hz](https://tex.z-dn.net/?f=1070000Hz)
But ![1Hz = s^{-1}](https://tex.z-dn.net/?f=1Hz%20%3D%20s%5E%7B-1%7D)
![\nu = 1070000s^{-1}](https://tex.z-dn.net/?f=%5Cnu%20%3D%201070000s%5E%7B-1%7D)
Finally, equation 2 can be used:
![\lambda = \frac{3x10^{8}m/s}{1070000s^{-1}}](https://tex.z-dn.net/?f=%5Clambda%20%3D%20%5Cfrac%7B3x10%5E%7B8%7Dm%2Fs%7D%7B1070000s%5E%7B-1%7D%7D)
Hence, the wavelength of a frequency of 1070 khz is 280.3 m.
<em>c. 835.6 MHz (common frequency used for cell phone communication) </em>
⇒ ![835600000Hz](https://tex.z-dn.net/?f=835600000Hz)
But ![1Hz = s^{-1}](https://tex.z-dn.net/?f=1Hz%20%3D%20s%5E%7B-1%7D)
![\nu = 835600000s^{-1}](https://tex.z-dn.net/?f=%5Cnu%20%3D%20835600000s%5E%7B-1%7D)
Finally, equation 2 can be used:
![\lambda = \frac{3x10^{8}m/s}{835600000s^{-1}}](https://tex.z-dn.net/?f=%5Clambda%20%3D%20%5Cfrac%7B3x10%5E%7B8%7Dm%2Fs%7D%7B835600000s%5E%7B-1%7D%7D)
Hence, the wavelength of a frequency of 835.6 Mhz is 0.35m.