Lab Assignment 6: MomentumInstructor’s Overview Collisions and momentum are something we experience everyday. Most of the collisions in our life are benign - bumping into a colleague in the hall, enjoying an evening of bowling, or competing in a billiards tournament. Some collisions, such as automobile accidents, are more serious. In these cases, advances in safety technology that leverage understanding of impulses and momentum have dramatically reduced fatalities. In this lab we will explore the concepts of impulse and momentum. This activity is based on Lab 12 of the eScience Lab kit. Our lab consists of two main components. These components are described in detail in the eScience manual. Here is a quick overview: In the first part of the lab, you will experiment with nearly elastic collisions using marbles. In the second part of the lab, you will put on your safety engineer’s hat and design a safe landing zone for an egg. Take detailed notes as you perform the experiment and fill out the sections below. This document serves as your lab report. Please include detailed descriptions of your experimental methods and observations. Experiment Tips: Instead of using a paper chute in the marble experiment, you can "flick" the marble(s) down the ruler groove to the stationary line of marbles as in this image: I recommend using hard-boiled eggs in the second component of the lab activity. They are less messy and serve as a handy snack after you complete the lab. Date: Student: Abstract Introduction Material and Methods Results Marble experiment Based on your results from the marble experiment, please answer the following questions: Whatkindofcollisionisexhibitedbythemarblesinthisexperiment,andwhy? Whenonemarblehittheendofthelineofmarbles,howmanyshotoffthe other end? Describe the momentum of the set of marbles before and after the collision (assume elastic collisions). Howdidthespeedofthemarblethatcomesofftheendofthelinechangeas you increased the speed of the marble that travels down the chute? Use what you know about the conservation of momentum to describe what is happening. Whathappenedwhenyousenttwomarblesdownthechute? Writedownthetotalmomentumfortwomarblesofmassmbothmovingat velocity v. What is the kinetic energy of the system? Whenyoudroptwoballsatonce,whydoesn’tonlyonemarblecomeoffthe end twice as fast? Write down the kinetic energy of one marble with mass m and velocity 2v and compare this to your answer in Question 4 to check. (Note that we are assuming the collisions are perfectly elastic, when in reality this is an approximation.) Egg experiment Based on your results from the egg experiment, please answer the following questions: 1. Didyoucomeupwithadesignthatpreventstheeggfrombreaking? Describe your approach in detail. Whydidaddinglayersofpaperworkbetterthanonethicklayerwiththesame number of sheets? (Hint: over how much time is the force applied in each case?) Whatdidyoudotoimproveyourapparatus? Explainhowacircusnetpreventstrapezeartistsfrominjuringthemselves even after falling from a large height. Whyitisimportanttobendyourkneeswhenyouhitthegroundafterjumping from several feet in the air? Conclusions References

Reflection Questions: Now that the course is over, what are your overall impressions or reactions to the course? To what extent was your learning experience positive or negative? What did you learn about writing from this course? About online education? About college courses overall? How did you approach this course? Were your approaches successful? Why or why not? What was the most important thing you learned about yourself in this course? What learning experiences will be most applicable to your life moving forward? What connections can you make between your prior knowledge about writing and the knowledge you gained in this course? What do you think you will do similarly in courses moving forward? What will you do differently or improve upon?