Question

Question #b30f3

Answer 1

The frequency of the light is 300 MHz in the radio frequency region.

Explanation:

The formula relating energy `E` and frequency `f` is

`color(blue)(bar(ul(|color(white)(a/a)E=hfcolor(white)(a/a)|)))" "`

where `h` is Planck's constant.

We can rearrange the formula to get

`f = E/h`

In this problem,

`E = 1.99 × 10^"-25" "J"`
`h = 6.626 × 10^"-34"· "J·s"`

∴ `f = (1.99 × 10^"-25" "J")/(6.626 × 10^"-34"color(white)(l)"J·s") = 3.00 × 10^8 "s"^"-1" ="300 MHz"`

This type of light is a radio wave. It is on the border between VHF and UHF frequencies.