Experiment 9: Lenses

Objective:
To observe the characteristics of converging lenses by placing an object on one side of said lens and observing the real, inverted image that is created on the other of the lens.

Equipment;

-Light box
-Converging lens
-Lens holder
-Meter stick
-Index card (or anything else to project the image on)

Procedure:

We determined the focus by having two lasers go through the lens and moving the board onto which they were projected around until they converged into one dot. The distance from this board to the lens was the focus.

For the second part of this experiment, we measured how the object distance affected the image distance and image height and recorded our results on a table. We varied the object distance by moving the lens further away and we obtained an image height by varying the position of the paper the image was projected upon until we could see a clear image.

Lastly, we evaluated what happened to the image when the object distance was at 0.5 f, we concluded that the image went to infinity (diverged).

Data/Calculations:
The table below shows the data we gathered:

We first plotted the image distance vs. the object distance and found that it possessed an inverse relationship:

By plotting the inverse of the image distance vs. the negative inverse of the object distance, we obtain a linear relationship that can be explained by the equation 1/s + 1/s' = 1/f.

Conclusion:
After plotting the inverse values and noticing that the graph is linear, it can be concluded that it is of the form y=mx + b. Substituting what y and x are the equation 1/q = -m/p + b. Comparing it to the standard 1/s + 1/s' = 1/f equation relating object distance s and image distance s' it makes sense that m is equal to 1 and b is equal to 1/f, we obtained a slope of .9 and a y intercept of .184 so we were very close to the actual values. This experiment proves that the object and image distance relationship works. There were some inaccuracies in our experiment and they were accounted for with uncertainties since it was very difficult to get accurate measurements.