Question

The wavelength of a radio wave varies inversely as its frequency. A wave with a frequency of 720 kilohertz has a length of 500 meters. What is the length of a wave with a frequency of 450 kilohertz?

.......... meters

Answer 1

800 meters

Explanation:

y is inversely proportional to x is the same as y is inversely proportional to
`(1)/(x),` that means

`y=(k)/(x).`

If a wave with a frequency of x=720 kilohertz has a length of y=500 meters, then

`500=(k)/(720)\\ \\k=500\cdot 720=360000.`

Hence, the length of a wave y with a frequency of x=450 kilohertz is

`y=(360000)/(450)=800`