Atruck driver is broadcasting at a frequency of 21.594 mhz with a cb (citizen’s band) radio. determine the wavelength of the electromagnetic wave being used. use 2.9979 × 108 m/s as the speed of light, and give your answer to five significant figures.

Wavelength = (speed) / (frequency)

Wavelength = (2.9979 x 10⁸ m/s) / (21.594 x 10⁶ /s)

Wavelength = 13.883 meters

Note:

Our truck driver won't find anyone to talk to, and he could be in real trouble.

The "Citizen's Band" in the US has 40 channels to talk on, spread between 26.965 MHz and 27.405 MHz.

21.594 MHz  is not a Citizen's Band frequency.  

-- If our driver driver bought a CB radio that transmits on this frequency, the radio was built and sold illegally.  It's not 'type-accepted' by the FCC for CB service, and people with CB 'license' certificates are not allowed to operate it.

-- If he built it himself, he's also in trouble.  People with CB 'license' certificates are not allowed to operate equipment that they build for themselves, (like 'ham' radio operators are).

-- Whether he built it or bought it, he's not allowed to transmit on 21.594 MHz with a CB 'license' certificate.

-- The CB antenna he buys at the super truck-stop on the interstate is designed for the legal CB channels, and it won't work very well at this frequency.  His transmit output power will come out low, and his receiver won't be very sensitive.

-- And finally, the only other people equipped to talk to him on that frequency are other people who also have illegal equipment like he has, and are also operating it illegally like he is.  Fortunately there still aren't too many of those.  As soon as he turns his radio on, he'll be amazed at how quiet the band is, and he very likely won't ever find anybody else to talk to.

Have a big ten-fawer there, Good Buddy !  Keep the bugs owf yer bumper, and say hi to Smokey for me.

the answer is b, have negligible mass