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Hi there.
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So for this problem, we have an experiment to measure the speed of light using the apparatus that is shown in here.
00:09
So the distance between the light source and the mirror, that distance d, is equal to 11 .45 kilometers.
00:25
And the wheel had 720 notches.
00:37
And what we need to determine is, well, we know that the speed of light is equal to 2 .998 times 10 to the 8 meters per second.
00:54
And we need to calculate the minimum angular speed of the wheel, for this experiment.
01:04
So to calculate that, oh, sorry, in here is just this.
01:10
And then we are going to start.
01:13
We know that by definition, we know that through the number of notches, it is possible to identify the angular displacement in revolutions.
01:23
That is to say that the angular change, oh, sorry, the change in the angular position is equal to 2 times pi over 720 radiance, where we have in here the value for the notches.
01:45
So, and now we can use kinematics for of motion to tell us the speed and of light can be expressed by the distance d divided by the time.
01:58
So if we solve for the time, we are going to have that the time is equal to the speed.
02:05
Now, in this case, we will have that the distance travel is two times d because the light has a round trip.
02:13
So we're going to have that this is two times the distance d divided by the speed of light.
02:20
So now we're going to use this in the definition of the angular speed...