What is the frequency of green light that has a wavelength of 547 nm?

Answer 1

Given: wavelength (λ) = 547 nm = 547x10^-9 m

Asked for: frequency (ν) = ?

Equation to use: c = λν

c = speed of light = 3x10⁸ m/s

λ = 547x10^-9 m

ν = ?

Note that both c and λ are in units of meters so they will cancel, leaving 1/s or Hz.

Solving for ν, we have...

3x10⁸ m/s = 547x10^-9 m * v

v = 3x10⁸ m/s / 547x10^-9 m

v = 5.48x10¹⁴ Hz = 548 THz (tera hertz) = frequency

Answer 2

frequency = velocity/wavelength

= 3x10^8/5.47x10^-9= 5.48 x 10^16

= about 547 or 548 THz for green light frequency when its wavelength = 547 nm

THz = Terahertz= 10^12 hertz

velocity is the velocity of light, a constant speed= about 300,000 km/sec = 671 million mph= 186,000 miles/second

all green light is within the range of 500 to 600 THz

Answer 3

The wave speed equation ( put this in your notes ) tells us that

Velocity of a wave (meters per second) = (wavelength in meters) x frequency of the wave (hertz) .

The shorter way to write this is simply V = λxf.

First we must recognize that this equation is set up to solve for velocity, not frequency. We already know the velocity of light, but we don't know the frequency; This means that we need to rearrange the wave speed equation until it says f = (something). Only then can we begin plugging in numbers.

V = λxf, so I divide both sides by λ , which gives me f = V/λ .

Now I know the velocity of light; it's V = 2.99 x 10⁸ meters per second (Put this in your notes as well).

I also know the wavelength is 547 nanometers. Unfortunately, I can't plug nanometers and meters into my calculator at the same time; it'll give me wrong answers if I do. So I gotta make the units match first.

Convert 547 nanometers into meters by remembering that nano means 10^-9, so 547 x 10^-9 or

0.000000547 meters. = λ

The meters on this answer matches the meters per second in my light speed, so now I can plug them into our rearranged equation.

f = V/λ, so f = 2.99 x10⁸ / 5.47x10^-9 which my calculator tells me is....

Also please notice that I'm doing division here to get my final answer. That was not obvious when you look at the wave speed equation; it says multiply. If you jump right to multiplying the first 2 numbers you can find, you'll never get the right answer because it's really a division problem. We can't see that until we rearrange the formula to get what we actually need.