2. The controlled amount of water that is poured in the Plexiglas.
3. Same converging lens for each replication
4. All of the replications will be at one of the following angles, 20°, 40°, and 60°
Procedure
Materials and Apparatus
- Ray Box
- Cold water( 4.5°C)
- Hot water (63 °C)
- Tap Water(36 °C)
-
Semi-circle Plexiglas
- 360° Protector
- Thermometer
- Beaker
Method
1) Gather all the materials listed in the materials list and then make 3 data collection tables for this experiment to record the results.
2) Pour the hot water that you have heated into the Plexiglas/Converging Lens and then place the Plexiglas on the protractor as shown below.
3) Plug the ray box to a power source
4) Then you must make sure that the cover for the ray box is set in which one ray of light is coming out of the ray box. There must be a single, linear ray of light should be coming out of the ray box.
5) Line the ray from the ray box with the 20° angle. The ray being emitted from the ray box must be pointed towards the convex side of the Plexiglas and then make sure that the ray is pointes towards the exact center of the protector .
6) The ray should pass through the Plexiglas with the hot water, and then be refracted on to the other side of the protractor ( it should be easier to read the refracted angle by placing a paper where you seem to see the refracted angle for a more accurate result).
7)Record the angle at which the refracted ray passes through on to your table.
8) Repeat steps 1 through 6 for the incident angles of 40° and 60° and record the refracted angles.
9) Repeat steps 3-7 again for the cold and tap water.
Method (data collection and analysis):
1) you must record the refracted angles on your data tables for each of the incident rays.
2) Calculate the sins of the incident angle and the refracted angle for the hot, cold and Tap water when done recording the refracted angles
3)After calculating the sins of the incident angle and the refracted angle for the hot, cold and Tap water you then must divide the sin of the incident angle with the sin of the refracted angle (sin i / sin R) then record your data.
4)When you are finished calculating sin i / sin R for the 20°, 30°, and 40° incident angles, you then must calculate the average of the 3 sin i /Sin R for each of the data tables .
5)When you finish use the recorded results to create a bar graph to record data on the average index of refraction for each of the different tables.
Results
Qualitative Results:
During the lab, one thing we noticed was that as the ray passed through the Plexiglas filled with water, the ray of was slightly bended and then on the refracted side the ray would be in a different angle each time.
Data Tables:
Table 1 : Incident angle, refracted angle, sin for the incident and refracted ray, and index of refraction for the Cold Water( 4.5°C)
Table 2: Incident angle, refracted angle, sin for the incident and refracted ray, and index of refraction for Hot Water( 63 °C)
Table 2: Incident angle, refracted angle, sin for the incident and refracted ray, and index of refraction for Tap Water( 36 °C)
Average Index of Refraction:
Graph:
Average Indexes of Refraction
Discussion:
Conclusion:
After our experiments we concluded that a light beam has a lower index of refraction when it is travelling through cooler water and higher when traveling through warmer temperature in water.
Evaluation of Procedure:
One limitation that we had in our lab was maintaining the temperature of the water. Once we pored the water in the beaker the room temperature altered the temperature of the water either if it was cold or warm resulting in a change of results. we noticed that the cold temperature water had a much different index of refraction from the warm and tap water. which means that if we maintained the temperature and not let the room temperature change the temperature in the beakers the results would have been more different.
Another limitation that we had in our lab was the lights in the room. the light in the room affected our refracted results due to the fact the beam was not clear enough to see in which we couldn't take accurate results.
Improving the Investigation:
We could improve our investigation by somehow maintaining the temperature that was originally suppose to be of the water and somehow not let the room temperature interfere with the temperature of the cold and hot water temperatures.
We could also improve the investigation by doing it in a very dark room with no lights on apart from the ray box. this would make it much easier to read the refracted ray and allowing us to make accurate results.
We can also somehow make to results more accurate if we had a more stronger beam in which the light refracted would be much more visible more accurate.
