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Researched by Cassi T.
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The purpose of this experiment was to determine if different colors of light bulbs would have different percentages of light pass through a prism.
I became interested in this idea when I wondered how prisms worked and so I decided to do a science project dealing with prisms.
The information gained from this experiment will help the manufacturers and users of the camera, binocular, telescope, etc. It will help them because they will know if different colors of light pass through a prism equally.
My hypothesis was that white light would have the highest percentage of light pass through the prism.
I base my hypothesis on the World Book Encyclopedia, volume 16, "The different colors in light are not refracted to the same extent. Because of this characteristic of light, refracted light beams often break up into the colors of the spectrum."
The constants in this study were:
- The same size of prism (about 4cm*4cm)
- The same room
- The same temperature
- The same source of light (light bulb)
- The same amount of light (twenty-five watts)
- The same distance from light bulb to prism
- The same distance from prism to light meter
- The same distance from light bulb to prism
The responding variable was the intensity of light.
To measure the responding variable I used a computerized light probe and measured the amount of light when it went through the prism and when there was no prism.
| QUANTITY | ITEM DESCRIPTION |
|
1 |
blue 25 watt light bulb |
| 1 | red 25 watt light bulb |
| 1 | white 25 watt light bulb |
| 1 | light meter |
| 1 | triangular shaped prism |
| 1 | camera |
| 1 | roll of film |
| 1 | piece of 2 cm. thick plywood (12*12) |
| 4 | pieces of 4 cm thick |
| 10-20 | screws |
| 1/2 | bulldog 18 gauge nails |
| 1 | porcelin fixture |
1. Gather all materials.
2. put the one right angle prism inside of box
in the slot
3. Make sure that the prism is securely inside
4. Take a light bulb out of the storage area.
5. Put the light bulb into porcelain fixture.
6. Close the door over the half where the
light bulb is and plug in the cord.
7. Measure the amount of light that the
light bulb has before it goes into the prism.
8. Copy the numbers from the 5 seconds from the
computer program into Excel.
9. As soon as the colors come out of the prism
you hold out the light meter stick towards the prism.
10. Repeat step 8.
11. Switch to the next light bulb.
12. Open the hinged door
13. Repeat steps 4-5.
14. Now repeat steps 6-11 again for next color.
15. Repeat steps 13-14 for the rest of
the colors of light bulbs.
16. Now do 4 more trials for each color
using steps 13-15
17. When the experiment is finished take the
first column and average it
18. Do the same for each of the other columns.
19. Take the first five columns of the averages
and average that.
20. Do the same for the second five.
21. Repeat steps 19 and 20 for the other colors
of light
22. Make a graph using data in Excel.
This picture shows the test box I used.
RESULTS
The original purpose of this experiment was to determine if different colors of light going through a prism and not going through a prism had different percentages of light measured in lux by a light meter stick.
The results of the experiment were that white light had the largest percentage of light that went through the prism.
My hypothesis was that white light would have the highest percentage of light going through the prism and green would have the least
The results indicate that this hypothesis should be accepted.
Because of the results of this experiment, I wonder if different wattages of light would produce similar results.
If I were to conduct this project again I would take more care in my work. I would have recorded all materials as I bought them, so I wouldn't have to go back and check them again and again to make sure I wrote them down.
I would like to thank the following people for their help with my science project.
Mr. Newkirk, who helped transport me to the junior high school so that I could do my science experiment.
Mr. McMillen, of the Selah junior high science department, who let me borrow his computerized light probe and for letting me do my science experiment in his classroom.
Mrs. Hostetler, a Selah Intermediate School 6th grade teacher, for helping me to fix up parts of my presentation that didn’t sound right to me, and for helping me to convert standard measurements into metric measurements.
I would like to thank my parents for helping get some of the supplies I needed. My mother for encouraging me that I could do it, and my father for believing in me and for having confidence.
Last I would like to thank my grandfather who helped me cut the boards with his table saw.
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