I would love to have some help with my pre-lab. I understand some of it but I would love to understand it all. Thank you so much in advance!

Phys 1125 Page 1 How do microscopes use lenses? Exploring Light and Lenses pre-lab Introduction Opticsthe subeld of physics focussing on the study of lightis Important to many areas of biology and engineering. The use of optics in biology has evolved from the simple light microscope used by Darwin to the complex, live-cell, high resolution microscopes used in current cuttingedge research. In engineering and ecology, the use of binoculars, cameras, and surveying scopes have followed suit. In this twoweek lab, we will be exploring how lenses can help us create images of small or distant objects. While contemporary microscopes and telescopes usually combine multiple lenses together, we will be exploring singlelens sys tems we are only beginning to learn about light. In this week's lab1 your task will be to determine the relationship between the focal length, f, image distance, 5,, and object distance, So of a device in which the object-toirnage distance is held a xed length, L. In order to do this, you will have to determine what data to collect, develop an experimental procedure for collecting those data, identify and reduce uncertainty, and model the rela tionship between the parameters. This pre-lab is designed to help introduee you to the ideas of geometric optics and statistical analysis if you have not yet. encountered these in class. Plan on spending roughly 45 minutes working on this. Pre- lab goals a Distinguish between parallel light rays and pointsource light rays o Distinguish between the focal point and the image - Quantity the \"goodness\" of a mathematical model of some data. . Quantify the "goodness" of a mathematical model of some data. Getting Set Up This pre-lab makes use of two PhET optics simulations. These both run in HTML5 and can play straight on the browser of any device. for the Bending Light PhET: . Visit the site https://phet.colorado.edu/en/simulation/bending-light and click play on the simulation thumbnail. . Select the "prisms" icon for the Geometric Optics PhET: . Visit the site https://phet.colorado.edu/en/simulations/geometric-optics and click play on the sim- ulation thumbnail. . Select the "lenses" icon 1 Optics Introduction Drawing light rays 1. In the Geometric Optics PhET, select "light" from the pulldown menu and "Many" from the "Rays" options. Describe what you see in words. Draw a picture of what you see. Optics portions adapted from the UMD NEXUS Team; Statistics components adapted from the work of N. Holmes, Cornell U. Phys 1125 Page 2 2. In the Bending Light PhET, set up the virtual laser to emit multiple beams of light. Draw whatPhys 1125 Page 2 2. In the Bending Light PhET, set up the virtual laser to emit multiple beams of light. Draw what you see. 3. One of thme setpups is called a \"Parallel ray\" arrangement and the other is called a \"Point source" arrangement. Which is which? Why? Fa cussing Light 1. In the Bending Light. PhET, place a circular lens in the path of the laser beams. This lens is called a \"biconvex lens,\" meaning that it bulges out on both sides. What. happens to the beams as they travel through the lens? 2. By replacing the hiconvex lens with the concave lens (one side is pushed inwards). Try mixing and matching these elements. You should see that some arrangements spread the light out as it passes through the lens and other arrangements bring the light together as it passes through the lens. The "spreading out" of the light is referred to as diverging. The \"bringing together'1 of the light is referred to as converging. In the space helmv, sketch some of the combinations which produce diverging and converging light rays. Converging Diverging Optics portions adopted from the UMD NEXUS Team; Statistics components adapted from the work of N. Holmes, Comet! U. Phys 1125 Page 3 3. Now look at the rays passing through a single lens (any lens]. Where on the lens does the diverg thronehthclcnscsi' Einhalcnnsetitunwiththclasnr Phys 1125 Page 3 3. New look at the rays passing through a single lens (any lens}. Where on the lens does the diverg ingfoonvcrging happen for light traveling through the lenses? Pick a lens, set it up with the laser emitting parallel rays, and examine how the incoming parallel rays are changed as they enter, travel through, and then leave the lens. Draw what you see in the space below. Effect of rays emitted by a light source Parallel rays or Point source? For incoming parallel rays, the circular leiconvex lens (or the semi-circular lens) will focuses the beams to- gether at the 'focal point' of the lens. We say that these \"parallel incident rays converge on the focal point of the lens.\" The distance from the center of the lens to this 'focal point' is called the focal length of the lens. 1. Maneuver the circular lens in front of the laser; Does the focal length change when the lens is brought closer to] farther from the laser source? Do you think it should change? Why or why not? Draw what you see in the space below and carefully label the focal length, I, of your lens. 2. Try putting a second lens in front of the laser: lghl'om clreullr' lll mum here This is similar to the \"point source" from the Geometric Optics PhET since the laser rays meet at a point before arriving at the circular lens. Maneuver the circular lens again {leaving the semicircular lens in place) and describe what happens to where the light. focusses {we call this point the image}; this time, does it change when the lens is brought closer to/ farther from the laser source? (As an alternative, you can. also try leaving the clrcular lens to place and moving the semicircular lens back and forth. Remember, we're asking about where the light focusses on the far stale of the circular lens). Optics portions adapted from the UMD NEXUS Team; Statistics components adapted from the urorlr of N. Holmes, Cornell U. Phys 1125 Page 4 3. Now let's compare these two situations. In words, what happens to the image location (relative to the biconvex lens) as you move the lens towards the parallel light source? Replacing the semicircular lens, what happens to the image location {relative to the biconvex lens] as you move the circular lens towards or away from the laser {but keeping to the right of the rst converganee}? Write a sentence or two to summarize the relationship that. you observe between the distance of the lens from the light source {the object distance, 30:}, the distance of the image from the lens {the image distance1 Si). .- . o .1 + CD Page view A" Read aloud T Add text 3. Now let's compare these two situations. In words, what happens to the image location (relative to the bi-convex lens) as you move the lens towards the parallel light source? Replacing the semi-circular lens, what happens to the image location (relative to the bi-convex lens) as you move the circular lens towards or away from the laser (but keeping to the right of the first convergance)? Write a sentence or two to summarize the relationship that you observe between the distance of the lens from the light source (the object distance, So), the distance of the image from the lens (the image distance, S;), and the focal length, f, of the lens. 2 Thinking about Fits So far when collecting data, you have been focussed on making comparisons between pairs of uncertain measurements. Often, it's more useful to plot continuous measurements and use fit lines to make and test predictions about models (which you'll be doing in this lab). Let's look at an example: Student A: y = 10x - 11 Student B: y = 11x - 21 100 stretch force uncertainty in force force [N measurement 40 [cm] [N] [N] 1 1 20 2 7 3 17 Student C: y = 5x - 3 Student D: y= x2 + 6 100 00 H H O0 00 00 H - K) 60 force [N] 40 20 Table 1: Stretch and Force data 33 7 1 S 70 9 90 8 1 1 8 Table 1: Stretch and Force data extension [rm| extension |r_n1] Table 2: Four different t lines for the same data. The above data are the results from a group of students who stretched a rubber band and collected values for both the force and the stretch. Each researcher in the group drew a different t line in order to model the functional relationship between force and stretch. We would like to determine which t line is the better model for the data and if we can improve on these. 1. Comparing two students, A and B, which one are you most condent represents a good fit to the data? Explain your reasoning. Optics portions adapted from the UMD NEXUS Team; Statistics components adopted from the work of N. Holmes, Comell U. Phys 1125 2. Comparing two students, A or C, which one are you most condent represents a good t to the data? Explain your reasoning. 3. Comparing two students, A or D1 which one are you most condent represents a good fit to the data? Explain your reasoning. :1. Invent at least two ways to quantitatively evaluate the quality of a t line to data. Your methods should allow you to compare which student's model is a better t to the data with a single number such that a smaller (but still positive) value indicates a better t. Try to test out your proposed methods on the data provided. The goal is to be creative and work with information to invent solutions to a problem. Your instructor will start lab with a discussion of of everyones ideas