[0:00]In this video, I'm going to teach you step by step how to determine the index of refraction of this glass block using close pin instead of laser. I'm going to use this laser just to show you the path of the light when it's traveling through this glass.
[0:30]The materials that are needed for this lab is a piece of cardboard or foam. A white piece of paper, the glass block. Take a note, a protractor, a ruler, about three close pins.
[1:10]Some coloring pens and a regular pen. First, you need to prepare this page, so fold this page like this and.
[1:46]Like this and then open it up. Place the ruler on this mark here and draw a vertical line. Turn your ruler and over that almost invisible crease when you, I folded the paper, so draw a horizontal line. This vertical line is the normal line, and the horizontal line is the boundary line. In this step, you need to place the protractor on the intersection between the normal line and the boundary line. Then press the protractor and select the following angles, make like a dot mark. 15 degrees, see here, 5, 10, 15 degrees, 20, 25, then you mark 30 degrees. 35, 40, 45 degrees, 50, 55, 60 degrees. So make sure that you can see all these angles. Remove the protractor and connect the selected angle with the intersection.
[4:00]In this step, place the block right under the boundary line. Mark the intersection with a close pin. Move the block right under the boundary line. Here we have two medians. This is air, and on this side is the glass block. Next, place a pin on your first angle which is 15 degrees.
[4:53]In this step, I'm going to try to align the red head and yellow head pins looking through the glass side.
[5:12]Then I have to look when the body of both pins align, which is right there. Then I'm going to use this third pin and place where both bodies align.
[5:43]Then I'm doing inspection. Now, I'm going to remove this pin and mark its location. In this step, I'm going to remove the block, and I'm going to remove this pin. Now, I'm going to connect this mark on the other side. This my intersection. Now, I'm going to place the protractor aligned here with 90 and I'm going to read this angle. So this angle is 10 degrees. So this is A, A1. I'm going to use a second piece of paper to record my information. I want to reuse this paper, so I'm going to fold like this. And as a title is Index of Refraction of a glass block.
[7:40]Make a table with five rows and four columns. The first row is the heading. So in this column, I'm going to record the lines. So my first one was A A1. This is my angle of incidence. My angle of incidence, my first one was 15 degrees. And my refracted angle is 10 degrees. Then I'm going to find the ratio between both angles, which is 1.5. Now, I'm going to do the same thing for my second angle, which is 30 degrees. Now, I will bring back, bring back the materials, which is my foam paper, this one, which is my paper where I prepare everything, the block, and the three, the three pins. I have here my three pins. Okay, I'm going to pin my second angle, which is 30 degrees. So this one here you'll be my intersection, and I will place the block right under the boundary line, and I am going to look align those pins just the body through the block. It's recommended for that you close one eye, just keep one eye open and one closed.
[18:17]I'm going to move the decimal to the left. So 1, 2, 3, 4, 5, 6, 7, 8. So I stopped right there. 2.05 x 10 to the 8 m/s. So this is how much the speed of light decreases as pass through the glass. So it was 3 x 10 to the 8 and now it's 2.05 x 10 to the 8. So through this experimental lab, I was able to calculate the index of refraction of this glass and also, I use the result to calculate the actually speed of light as traveling through this glass.
