Elisa Alvarado, Sarah Cratem, Ryan Partain, Julia Reidy
Mr. Thomas
AP Physics 2 cmod
1 March 2016
Unit 9: Light Wave Model Lab Report
Objective: To determine the effect of object distance on image distance and height for both red and blue lights.
Apparatus:
Procedure:
- Set up the blue light in a fixed position on the magnetic board.
- Place the object 16.5 cm away from the light, and use a marker board to view the image, moving it toward or away from the light as necessary to view the focused image.
- Record the image distance (distance to the marker board from the light) and image height.
- Repeat steps 2-3 for object distances of 21 cm, 23 cm, 25 cm, 27 cm, 29 cm, 31 cm, and 39.5 cm.
- Set up the red light in a fixed position on the magnetic board.
- Place the object 16.6 cm away from the light, and use a marker board to view the image, moving it toward or away from the light as necessary to view the focused image.
- Record the image distance (distance to the marker board from the light) and image height.
- Repeat steps 6-7 for object distances of 17.1 cm, 18.4 cm, 20.3 cm, 22.3 cm, 24.3 cm, 27.2 cm, and 38.6 cm.
Data:
Blue Light:
Image Distance vs. Object Distance
This thth
Th
1/ Image Distance vs. 1/ Object Distance
1/di=-0.954(1/do)+0.059cm
-Image Height/ Object Height vs. Image Distance/ Object Distance
-Hi/ho=0.892(di/do)
Red Light:
Image Distance vs. Object Distance
1/ Image Distance vs. 1/ Object Distance
1/di=-1.106(1/do)+0.066
-Image Height/ Object Height vs. Image Distance/ Object Distance
-Hi/ho=0.968(di/do)
Conclusion: The relationship between the two variables, the image distance and the object distance, was hyperbolic. Some constants in the experiment were the lights used. For example the same exact blue light and same exact red light was used throughout the experiment. The lights were also kept at a fixed position on the magnetic board. The material the light traveled through was constant throughout the experiment as well. The equation we got from our data showed that as di/do increased, hi/ho also increased proportionally. The equation from this data is hi/ho=0.968(di/do). To generalize this even more, you can see that (image height/object height)=0.968(image distance/object distance). The slope that we attained was slightly off because we could not maintain a perfect experiment since the slope was supposed to be a value of 1. Therefore, the general equation we derived from our data was hi/ho=di/do(1)=M. Since the value of the slopes were all around 1, another equation that shows the relationship between focal length (F), object distance (do), and image distance (di). This equation can be generalized to show that 1/F=1/do+1/di. Our data is not exactly correct due to errors during the experiment. For example, we determined when the image was in focus or out of focus using the human eye and judgement. This was likely to give us slightly incorrect values for each trial. We also had to measure a shaky image with a ruler. The image was shaky because lab members had to hold the light in place while we measured the heights and distances. Our values could have been slightly off due to the shaking of the lasers.
