10/4 Experiment 10: Lenses

First, we went outside under the side to figure out what is the focal length for the magnification glass has, the number we got was 24.5 and 24.3 cm, which the average is 24.4cm.
Later on we use the magnification glass and a light source with a figure in the front to project the image over a certain distance.

The data we obtained

Object distance,cm	image distance,cm	Object height,cm	Image height,cm	M	Type of image
5f=122	30.9	3	0.8	0.267	inverted
4f=97.6	33.3	3	1.05	0.35	inverted
3f=73.2	37.3	3	1.6	0.533	inverted
2f=48.8	48.4	3	3.15	1.05	inverted
1.5f=36.6	70.9	3	5.7	1.9	inverted

If we put the object within the image, we cannot see the image, the image will become infinite

if we graph di vs. do



 the inverse fit on the loger pro does not work perfectly, thus we will consider to plot the inverse di vs. negative inv do

According to formula: 1/do + 1/di = 1/f. As we expected, the 1/y-intercept will give us a value of 25 cm, which is gonna be the focal length.  And the slope of the regression line is suppose to be 1 as we have

 Both the values of focal length are within their uncertainties, the uncertainties from where we obtained under the sun is 24.4 +- 0.2cm . The uncertainties for data uncertainties is 25.1 +- 0.4cm

 The data can be consider to be math to each others within their uncertainties. We can measure the focal length of the magnification glass with two methods, one by using a sun and focus to a point and measure the height, or by using a known object distance and image distance to calculate the focal length. The only problem with the method 2 is when we try to focus the image on a white board, it is really hard to tell if the image is in focus or not when the image distance is far away from the lense due to the decreasing in light intensity.