00:01
All right, so this problem is kind of a real -world application kind of idea of the amount of energy it takes to give you sunburns or fade your clothes from light, right? so the wavelength that they're giving you is 375 nanometers getting ahead of myself.
00:19
We're going to be changing that to frequency so we can plug that into our energy is equal to planck's constant times frequency, right, to get the energy.
00:31
Since that's what we ultimately want.
00:34
We'll begin with, we're going to want to put in our speed of light, which is 2 .998 times 10 to the 8 meters per second, and we're going to do that over your wavelength that's given.
00:49
They give you 375 nanometers.
00:51
However, we want that in meters, so that way we can get our frequency.
00:56
So you're going to divide that by billing, which is the equivalent to multiplying it by 10 to the, the negative 9 and that gives you meters and from there we're able to find that our frequency is 7 .99 times 10 to the 14th hurts or per second and now we're going to use the equation i just mentioned e equals hb right and so all we're doing is plugging in plinks constant so that's this one and there's where frequency comes in.
01:44
There's exponents.
01:46
And look at that.
01:51
Now all you have to do is multiply...