00:01
Problem 11 from chapter 6 is asking us to determine the frequency and energy of a wave with a wavelength of 2 .09 times 10 of the minus 11 meters.
00:15
The way we're going to do that is we're going to use these two equations here.
00:18
So one relating the speed of the wave, wavelength and frequency, and then planx equation, which relates energy, plank's constant, and frequency of a wave.
00:27
So we've been given the wavelength of the x -ray and wavelength is represented by lambda.
00:34
So let's go ahead and solve for frequency using this equation here on the left.
00:40
So to do that, let's rearrange this equation so that the frequency is on one side.
00:46
So we'll divide the speed of the wave by the wavelength.
00:51
And when we rearrange the equation, looks like that.
00:57
And speed is a constant so we know that already and then we were given the wavelength in the question which is 2 .09 times 10 to the minus 11 meters so we can go ahead and plug those values in already and when we plug them in this is what we get so this is c this top value here and then when we divide speed by the wavelength this is the answer that we get for the frequency so one point 434 times to the 19th second inverse because these meters here cancel out.
01:33
And so you're left with second inverse, which is the correct unit for frequency...