Lab Write-Up Format THIS OUTLINE WILL HELP YOU TO WRITE OUT YOUR LABS. There may be changes or modifications but all elements must be included in your lab write-up. Each section on your lab paper must include a heading (as in Purpose: ) I. TITLE: Separate front page, as given in your text book, handout, or by the teacher. Ensure you provide your name, date, class, block, and teacher s name in the bottom right hand corner. II. PURPOSE: Sometimes referred to as the "PROBLEM" in the text, handout, or by the instructor. This will be a short description of the purpose of the lab answering the question: "Why are we doing this lab?" (marked out of 2) III. THEORY: A brief explanation (1-3 paragraphs) of the principles in physics or chemistry that you are about to investigate. Where do the equations come from and what do you hope to prove with them. Use diagrams where applicable. (marked out of 3) IV. MATERIALS: This is a recipe list of the materials that must include size, shape, color, and quantities used in the lab. (marked out of 1) V. PROCEDURE: Written out step-by-step instructions referring to all materials, times, etc. to be used in this lab. A proper procedure is written in a manner that would allow someone to reproduce your exact lab to the exact detail. DO NOT COPY THE PROCEDURE PROVIDED FOR YOU. You may summarize it but be specific for what you actually did in your lab. (marked out of 3) VI. OBSERVATIONS / DATA COLLECTION: There is always some kind of data that needs to be taken down during an experiment. This section includes the notes you collect like the times, temperatures used, mass quantities, the good things that happened and the bad. If possible, data should be in a graph or chart. Sometimes data tables will be provided for you. (marked out of 6) VII. ANALYSIS This is where the calculations and graphs go. (mark varies on each lab) VIII. ASSIGNED QUESTIONS: Often part of the analysis. Answer all questions in the procedure of the book or any of the additional questions at the end of the lab that the instructor assigns. Often the questions are set up to help when you are thinking about your conclusions. (may not be in every lab) (mark varies on each lab) IX. CONCLUSION: THE MOST IMPORTANT PART OF THE LAB!!! This is a paragraph, or two, or more depending on the magnitude or the lab, that tells the reader what you learned, or at the very least what you were supposed to have learned but didn t due to errors for whatever stated reasons. The errors must be the systematic errors that you have no control over. Measuring wrong is not considered a reasonable source of error for any lab. The conclusion will also be the place where recommendations are suggested for future improvements as we as citing any relevant applications to the real world. (marked out of 6)
Lab Report Rubric: Hand in with lab /1 Name: Date: Purpose /2 0 Below expectations Getting there Meets expectations present Purpose not clear. Clearly defined purpose with a focused topic of study. Theory present Errors in theory or relevant equations are not explained. Theory introduces the topic and explains all the necessary equations. Theory introduces the topic and thoroughly explains all the necessary equations and the rationale behind it all. (Diagrams used) Materials /1 Missing materials. = 0/1 All materials present. Procedure Some steps are there. Mainly incomplete. Steps are there, but 1-2 or more important elements are missing. Specific and reproducible. (If you gave this to someone to do, could they do it?) Observations /6 Analysis (questions) /12 (Example calc.) Conclusion /6 Missing either a qualitative or quantitative observation, or quantitative observations are inaccurate. Data is poorly analyzed with no inferences made. No example calculations shown. Minimal: Conclusion there, but minimal link to original problem, application is not relevant, no sources of error listed. Qualitative and quantitative data are present and correct. Data is analyzed with vague inferences made. Answered all assigned questions correctly. Adequate: Conclusion is adequate, the problem is adequately referenced, application is vague, and only one source of error is identified. Qualitative and quantitative observations are accurate and clearly organized using charts where necessary. Thorough investigation of data collected and clear inferences are stated. Example calculations clearly demonstrate how the data in the tables and graphs relate to each other. Effective: Problem is answered (supported or refuted) based on data. Relevant application made. Future improvements to lab are listed. At least 2 sources of error are identified. Format Far below grade level. Many errors in format, grammar or spelling, and work is not neat. Some errors in format, grammar or spelling, and work is mostly neat. No errors in format, grammar or spelling, work is neat, AND a title page is present. Total: 40
Investigation: Refraction of Light Problems: 1. How is light refracted when it passes from air into an optically denser medium? 2. How is light refracted when it passes from glass into a medium that is less optically dense, like air? Theory: Explain Refraction. Use words, equations, and diagrams. Materials: Single slit ray box (or laser) Semi-circular glass block Polar co-ordinate paper Graph paper Ruler Protractor Procedure: PART I: Air to Glass 1. Place the glass block on the polar co-ordinate paper, as illustrated. Label each division on the polar co-ordinate paper beginning on the right, then moving upwards, 0-90. Then back down to 0 as you continue to move left. Repeat this on the underside of the polar co-ordinate paper. 2. Direct a single ray of light at the flat surface of the glass, along the normal. Make absolutely sure that the ray passes through the centre of the flat surface. Measure the angle of refraction, and record it in your notebook in a chart, as illustrated below. 3. Repeat the procedure for angles of incidence of 10 through 80 in increments of 10. PART II: Glass to Air 4. Draw another chart in your notebook and repeat step #1. 5. Direct a single ray of light at the convex surface of the glass, along the normal. Make absolutely sure that the ray passes through the centre of the flat surface within the glass block. Measure the angle of refraction, and record it in your notebook in a chart, as illustrated above. 6. Repeat step 3. Observations Include all qualitative and quantitative observations in this section, including your polar graph paper.
Questions/Analysis 1. When the light travels at an angle from an optically less dense medium to an optically denser medium, e.g., air to glass, how is the light bent in relation to the normal? At what angle of incidence is there no bending? 2. Determine the value of the ratio? sin i sin R ratio for each pair of angles. What conclusion can you make concerning the sin i sin R 3. When light travels from an optically denser medium to a less optically dense medium, e.g., glass to air, at an angle greater than 0, how is it bent in relation to the normal? 4. What is the value of the determined in #2? sin i sin R 5. Why is there no refraction at the curved surface in all cases? ratio for glass-air interface? What is the relationship between this value and the value 6. What other phenomenon occurs increasingly as the angle of incidence increases? 7. What happens to the light, between 40-50, once it reaches the boundary between the glass and the air? 8. At what angle of incidence is the angle of refraction 90? Determine the answer experimentally and check your answer mathematically. 9. What specific type of glass were you using? Conclusions Summarize your lab and state your concluding remarks regarding the laws refraction. State any apparent errors and how severe those errors would have impacted your data. Provide possible improvements for future experiments in a similar nature. Try to think of some possible applications regarding refraction of light such as you have observed here.
Part 1 Air into glass
Part 2 Glass into air