# Question #0daec

##### 2 Answers

#### Explanation:

From the definition of velocity,

Thus by ratio and proportion, if one wavelength is 600nm, then

#### Explanation:

The idea here is that you need to consider the speed of light *constant* and use its known value to calculate how many wavelengths would fit **per meter** of distance traveled.

As you know, the speed of light can be *approximated* to be equal to **every second** light travels a distance of

Now, a *nanometer*, or

The conversion factor between these two units will thus be

#"1 m" = 10^9"nm"#

At this point, a unit conversion will take you from *meters* to *nanometers*

#3 * 10^8 color(red)(cancel(color(black)("m"))) * (10^9 "nm")/(1color(red)(cancel(color(black)("m")))) = 3 * 10^(17)"nm"#

Since one wavelength covers

#3 * 10^(17) color(red)(cancel(color(black)("nm"))) * "1 wavelength"/(6 * 10^2color(red)(cancel(color(black)("nm")))) = color(green)(5 * 10^(14)"wavelengths")#

The answer is rounded to one sig fig, the number of sig figs you have for the wavelength of the emitted light.