Laboratory Manual College Physics for AP Courses Lab Manual by OpenStax (Student Version)

Laboratory Manual College Physics for AP Courses Lab Manual by OpenStax (Student Version)Table of Contents Information for the Student Lab 1: Graphing Motion Lab 2: Projectile Motion Lab 3: Newton’s 2nd Law Lab 4: Forces Lab 5: Circular Motion Lab 6: Hooke’s Law and Spring Energy Lab 7: Impulse and Momentum Lab 8: Conservation of Momentum Lab 9: Simple Harmonic Motion Lab 10: Rotational Motion Lab 11: Mechanical Waves Lab 12: Sound Waves Lab 13: Electrostatics Lab 14: Ohm’s Law Lab 15: Resistor Circuits Lab 16: Kinetic Theory of Matter Lab 17: Gases Lab 18: Fluid Dynamics Lab 19: Thermodynamics Lab 20: RC Circuits Lab 21: Observations of Magnetic Fields Lab 22: Quantitative Magnetism Lab 23: Electromagnetic Induction Lab 24: Mirrors Lab 25: Geometric Optics Lab 26: Light as a Particle Lab 27: Double-Slit Interference and Diffraction 4 5 9 171 177Lab 28: Atomic Physics Lab 29: Models of the Hydrogen Atom 185 190 5This content was originally authored through a collaboration with the Texas Education Agency (TEA). It is presented here with modifications, including updates to align with the 2019 Course and Exam Description for AP Biology. These resources are available to all verified instructors free of charge at the following hyperlink: courses?Instructor%20resources. To the Student: Congratulations on being accepted into, and having the courage to take, an Advanced Placement biology class! You are about to delve deep into some very detailed biology concepts. This lab manual aims to help you better understand these concepts through hands- on experiences in the laboratory. In addition, it will challenge you to critically think about biology concepts, scientific methods, and experimental design as part of its inquiry-based framework. Inquiry-based learning involves challenging yourself to learn through self-discovery. Instead of simply presenting you with facts to memorize, this manual encourages you to ask questions about the material that you will then answer through your own exploration. By creating your own hypotheses and then planning and carrying out your own experiments on a variety of topics in the lab manual, you will hopefully learn biology by satisfying your own curiosity. In this AP lab manual, the inquiry-based structure includes the following components: 1. Pre-assessment section. This section contains a list of questions that you should answer before starting each activity. These are meant to get you thinking about the main concepts of each lab. The pre-assessment questions are designed to connect the concepts in each lab to your experiences in daily life. Whether you realize it or not, you observe biology constantly in the world around you. Therefore, you are likely familiar with more biology topics than you realize! The pre-assessment questions are meant to tap into the biology knowledge you already have and apply it to what you will learn in each lab. As a result, your answers to these questions may not be graded and you will benefit greatly by discussing your answers as a class. This also allows your teacher to measure how familiar you and your classmates are with the material. 2. Structured Inquiry. In this section, you will be introduced to an experimental system by doing a well-laid out experiment with detailed steps. This section is meant to guide you in using the equipment in a “safer” activity before planning and performing an entire experiment. However, you will still be posing questions, predictions, and hypotheses in the structured inquiry. You will also critically think about how to achieve the most accurate and reliable results during the structured inquiry in preparation for creating your own experiments in the guided inquiry. 63. Guided Inquiry. In the guided inquiry, you will use the familiarity you gained during the structured inquiry to perform your own self-investigation. The experimental setup of the guided inquiries is often identical to that used in the structured inquiry. Therefore, you will be working with equipment and methods that you have already tried in the structured inquiry. This time, you will pick a variable to study, create a hypothesis, and fully design an experiment to test your hypothesis. You will determine which equipment and methods you should use to collect accurate and precise data. 7Once you have planned your experiment, be sure to have your plan approved by your teacher, who will also ensure that your plan is safe and appropriate for the equipment available. Finally, you will analyze your own data and make conclusions based on your experimental evidence. If time allows, you will then refine and re-run your experiments or test additional hypotheses that you find interesting. In many ways, the guided inquiry step is meant to engage you in the same processes that scientists have used to discover information about our world and universe! Components of Structured and Guided Inquiry Sections To ensure that an inquiry-based approach is implemented in each activity, both the structured and guided inquiries also contain each of the following steps at least once: Hypothesize/Predict: This is where you will be creating hypotheses, which are questions or predictions about what will happen during an experiment. Be sure that your hypotheses are clear, specific, and testable. Good hypothesis: The volume of water in a container will be higher when a 2-gram mass is added compared to when a 1-gram mass is added. Poor hypothesis: The volume of water in this experiment will increase as larger objects are added. Good hypothesis: The speed of a vehicle traveling down the 30ᵒ ramp will be lower than the speed of the vehicle traveling down the 60ᵒ ramp. Poor hypothesis: The vehicle will travel fast down the ramp with the greater amount of slant. Student-led Planning: Each inquiry contains at least one step where you and your lab partners will plan how to properly conduct your experiment. During the Structured Inquiry, you will generally plan proper techniques for getting the best results possible using the available equipment and described methods. As with many things in life, two or more heads are often better than one, and you and your group members should come to a consensus on a plan before proceeding. This will lay the groundwork for the Guided Inquiry; you and your group will need to plan an entire experiment in this step. Critical Analysis: This step typically occurs near the end of each inquiry. Here you will critically analyze your results, judge their validity, and explain why your hypotheses were supported or not supported by your results. You will also suggest ways that your experimental methods could have been improved to get more accurate or precise data as well as determine new questions to ask related to your results. A Note About Your Notebook As part of the challenge of taking an AP course, this lab manual does not contain data tables where you record your findings. Therefore, you will be required to design your own tables, answer assessments, and do any other note-taking in a separate notebook. You should use 8the same notebook for biology lab throughout the year. This will allow you to easily refer back to previous labs when you need to reference earlier content. Do not put non-biology content in your biology notebook, as your teacher may collect and grade your notebook throughout the year. 9Components of a Lab Main introduction: Each lab contains an introductory section under the title. This introduces the “big picture” concepts of the lab as well as how they connect to everyday life. They will also introduce the pioneering physicists and experiments that led to our current knowledge of each lab topic. Relevant equations that you will use in the labs are also introduced here, including definitions of their variables. Many of the labs involve measuring the value of these variables so that you can later perform your own calculations. Please read the lab and activity introductions carefully before your lab period. Then, before the lab starts, ask your teacher about any concepts of which you are unsure. In this lab you will learn This section presents learning objectives for the lab. These are the “take away points” that you should be able to explain or perform after doing the activities. It is helpful to read these objectives before each lab to prime yourself for what you will learn. It is then helpful to reread these at the end of each lab to ensure that you have achieved all of the learning objectives. Activities: Each lab is divided into 2-3 activities. Please note that your teacher may or may not have you perform all activities in a given lab, so pay close attention to your teacher’s instructions throughout the lab. Safety precautions: These bullet points list important safety issues that will prevent injury to yourself or your classmates during the lab activities. Each activity has its own safety precautions section. Please read and understand all safety precautions before beginning each activity! For this activity you will need section: This section lists all of the materials needed for each activity. Before you start the lab, make sure that you can identify all items on this list. Also, pay close attention to your teacher’s instructions, as you may be using different equipment for these labs than those on this list. Activity introduction: These are short introductions relevant to specific activities. As with the main introduction, the activity introductions may contain formulas, equations, or other background information needed to successfully carry out and understand the activities. As with the main introduction, please read these introductions carefully before your lab period. Then, before the lab starts, ask your teacher about any concepts of which you are unsure. 10Process steps: These are the steps you will perform to carry out the activities. Please read through all of the process steps and setup diagrams before starting Step 1. Ask your teacher if there are any steps you don’t understand prior to starting. This will help you perform the activities correctly the first time, preventing the need to redo activities or having to leave your laboratory period with unusable data. 11Assessments: The assessment sections provide questions that test your knowledge of the lab material. Your teacher will instruct you on how to submit answers to the assessments for grading. College Board® (CB) Standard Alignment: College Board® standards are summarized in a table format at the beginning of each lab. The College Board’s® AP Biology Course and Exam Description was used to provide this information. In addition, standards tags are found on the assessments, allowing you to quickly identify which standard is addressed by each question. 12Lab 1: Graphing Motion 9In this lab you will learn ● how to measure the speed of an object traveling at a constant velocity ● how to differentiate between motion at a constant velocity and motion with acceleration ● how to use a position or velocity versus time plot to understand motion Activity 1: Pre-Assessment 1. Would you expect an object that you set in motion to continue moving at a constant speed? Why or why not? 2. Discuss the answers to question 1 with the class. Activity 1: Constant Velocity Suppose you graphed the motion of an object using the horizontal axis for the time elapsed, in seconds, and the vertical axis for the distance traveled. For an object traveling at constant speed, the change in distance would be proportional to the change in time. Therefore, when you plot your data on a distance-versus-time graph, the points should fall along a straight line. However, every measurement has some error, so the data points would not be likely to exactly fall on a straight line. Using a line of best fit helps to average these errors and give a more accurate approximation. To draw a line of best fit, you would use a ruler to draw a straight line that follows the trend of the data and comes as close to all of the data points as possible. The slope of that line is given by The slope equals the speed of the object. Because of measurement errors, some points will lie above the best-fit line and some will lie below it. This is because the best-fit line passes through the middle of the data and averages the values. As a result, the slope of the line of best fit provides a more accurate value of the speed than a single pair of data points would. Safety Precautions ● Keep the cart on the track to avoid damage or injury. For this activity, you will need the following: ● Straight track* ● Cart with spring ● Stopwatch* ● Masking tape* ● Meter stick 10For this activity, you will work in pairs. *Note—If you have access to air tracks, using them will improve your approximation of a frictionless system that can move at a constant speed. **Note—For increased accuracy, photogate timers or other technology can be used in place of the stopwatch and masking tape. The distance between the photogate timers would replace the distance between pieces of masking tape, and the timers instead of a stopwatch would record the time. 11Structured Inquiry Step 1: Place your track with one end against a wall. Rest the cart against the wall, as shown in Figure 1.1, so that releasing its spring can launch the cart. Place one piece of masking tape on the track ahead of the starting position of the cart and another piece of tape further down the track. Measure the distance between the two pieces of tape. Create a data table in your notebook for recording the distance and travel time for the cart’s motion. You will be moving the second piece of tape at least three times, so you will need space in the table to record at least four separate times and distances. Figure 1.1: The speed of the cart can be measured by using the spring to launch the cart from the wall and then measuring how long the cart takes to travel a fixed distance. This can be done either by having it pass through two photogate timers or by using a stopwatch to measure the time of travel between two pieces of masking tape. Step 2: Hypothesize/Predict: Knowing that, ideally, the cart should move at a constant speed, predict how your measurements would change as you vary the location of your second tape marker. How would this prediction differ if the cart did not move at a constant speed? Realistically, do you expect your data to resemble the ideal situation? Step 3: Student-Led Planning: You will now use your photogates, or a stopwatch and meter stick, to measure the speed of your cart. You should vary the position of your second piece of tape or photogate timer to measure the speed for at least four distances. If your class uses photogates, listen closely to your teacher’s instructions on how to use them. Discuss with your partner what data you need to collect and how to use the data to determine the speed of the cart. Step 4: Critical Analysis: Record the time it takes for the cart to travel each distance in the data table in your notebook. Then calculate the speed of the cart for each trial, as well as the average speed across all trials. Were the predictions you made in Step 2 supported by your data? Why or why not? How could you improve your results? Discuss your answers with your partner and then write them in your notebook. Guided Inquiry Step 1: Hypothesize/Predict: Is this experimental setup a good choice for observing motion at a constant speed? What potential issues does it have, and what improvements could you make? 12Step 2: Student-Led Planning: Discuss with your partner how to use the data in your table to plot a graph from which you can determine the speed of the cart. Now plot your data and use the graph to find the speed of the cart in your experiment. Step 3: Critical Analysis: How did the speed you calculated using your graph compare with the speeds you calculated for each trial, and the average speed across all the trials, in your table? Which is a better method for measuring the speed of the cart, and why? Did your graph look as you expected for an object moving at a constant speed? Discuss your answers with your partner and record them in your notebook. 13Assessments 1. Consider a baseball player who hits a home run and runs around all of the bases on the field. a. Considering that he started and ended at home plate, is the distance he traveled equal to zero? What about the displacement? Explain. b. Is the player’s average speed over his entire base run equal to zero c. Based on this, is it important to know the path an object followed to calculate its speed, or do you only need to know where and when it started and ended? Explain. 2. In a particular city, each block is 50 m long. A runner goes two blocks north in 10 seconds, then five blocks south in 20 seconds, then eight blocks north in 50 seconds. a. Plot the runner’s distance traveled as a function of time. b. Calculate the runner’s speed for each interval. c. Calculate the runner’s average speed for the entire run. 14Activity 2: Pre-Assessment 1. What does it mean for an object to travel at constant acceleration? How could you set an object in motion at constant acceleration? 2. Describe at least two different types of accelerated motion. 3. Discuss the answers to questions 1 and 2 with the class. Activity 2: Constant Acceleration An object is accelerating if its velocity is changing. The acceleration a of an object is calculated by dividing Δv, the change in the object’s velocity, by Δt, the time over which the velocity changed The SI unit for acceleration is m/s2, or meter per second per second. The slope of a position versus time graph for an accelerating object is still the object’s velocity, but, by definition, the velocity of an accelerating object is changing. However, for an object with constant acceleration, the slope of the velocity versus time graph is and the graph should be a straight line whose slope is the acceleration. Safety Precautions ● Keep the cart on the track to avoid damage or injury. ● Limit the angle of incline of the track to less than 10°, so that the cart reaches the end of the track at a reasonable speed, avoiding damage or injury. For this activity, you will need the following: ● Straight track ● Cart ● Stopwatch* ● Masking tape* ● Meter stick ● Ring stand or blocks For this activity, you will work in pairs. *Note —For increased accuracy, photogate timers or other technology can be used in place of the stopwatch and masking tape. The distance between the photogate timers would replace the distance between pieces of masking tape, and the timers instead of with the stopwatch would record the time. 15Structured Inquiry Step 1: Position the track so that one end is slightly lifted above the ground, using either the ring stand mounts or blocks. Using your meter stick, place pieces of masking tape along the track to divide the track into five even intervals, as shown in Figure 1.2 Create a data table in your notebook to record the distance and time for the cart’s motion. Figure 1.2: A cart that is free to move on an incline will accelerate and will have different velocities at different locations. Step 2: Hypothesize/Predict: Now that the track is no longer horizontal, predict what should happen to the speed of the cart as it travels down the track. How will this differ from the motion of the cart at constant speed? Step 3: Student-Led Planning: You will now use your stopwatch to measure the speed of the cart as it travels different distances down the ramp, starting from rest. Discuss with your partner what data you will need to collect in each trial to measure the average speed for the given distance. Explain in your notebook why the final speed at the end of this distance is twice the average speed if the cart starts from rest. Be sure to think carefully about the start and end points you choose for each measurement of the cart’s speed. Your procedure may be different if you are using photogates to time the arrival times at several different locations in each trial. Step 4: Record the time it took for the cart to travel between each marker in the data table in your notebook. Calculate the final speed of the cart at the end of each interval. Given that the cart started at rest, calculate the acceleration of the cart for each interval, and calculate an average value for the acceleration across the trials. Step 5: Critical Analysis: Were the predictions you made in Step 2 supported by your data? Why or why not? What methods could you have used to improve your results? Discuss with your partner and then write your answers in your notebook. Guided Inquiry Step 1: Hypothesize/Predict: What makes the experimental setup here different from that in Activity 1? How will that make your graphs different from those in Activity 1? What do you expect the position and 16velocity versus time graphs to look like for your data? Step 2: Student-Led Planning: Discuss with your partner how the data in the table you created can be used to create position and velocity versus time graphs and how you can use these graphs to determine the acceleration of the cart. Now plot your data and use the graph to find a value for the acceleration of the cart in your experiments. 17Step 3: Critical Analysis: Given that gravity accelerated the cart down the ramp, does the value you measured for the acceleration of the cart make sense? Why or why not? Did your graphs look like you expected for an object moving with constant acceleration? Did the value you calculated using your line of best fit agree with the average value from your trials for the acceleration? Discuss your answers with your partner and record them in your notebook. Assessments 1. How does the acceleration of a cart on an incline relate to the angle of the incline? Give an expression that relates the acceleration of the cart, acceleration due to gravity, and the ramp angle. Assume that friction can be ignored. 2. If a car speeds up from rest to 30 m/s in 6.0 seconds and then returns to rest in 12.0 seconds, what is its acceleration? a. While speeding up? b. While slowing down? 3. In the first activity, you observed the motion of a cart moving at constant speed. However, the cart started at rest and then began moving. Therefore, the cart did accelerate in Activity 1 because the velocity changed. How did one experimental procedure produce motion at constant speed whereas the other produced accelerated motion?