Question

The brightest light detected from the star Antares has a frequency of about 8 X 10 to the power of 22 Hz. What is the wavelength of this light?

Answer 1

`3.75*10^-15` meters

Explanation:

Wavelength is given by the equation:

`lambda=v/f`

where:

• `lambda` is the wavelength in meters

• `v` is the velocity of the wave or radiation in meters per second

• `f` is the frequency in hertz

All stars emit electromagnetic radiation, which travels by `"EM"` waves at the speed of light, `c=3*10^8 \ "m/s"`.

The wavelength of this light is therefore:

`lambda=(3*10^8 \ "m/s")/(8*10^22 \ "Hz")`

`=(3*10^8 \ "m"color(red)cancelcolor(black)("s"^-1))/(8*10^22color(red)cancelcolor(black)("s"^-1)) \ (because 1 \ "Hz"=1 \ "s"^-1)`

`=3.75*10^-15 \ "m"`