Well here we are, trying to do a lab that I was never able to make function. What I wanted to help you build was a device that could generate charge continuously. Otto von Guericke built the first one of these in 1663. He made a sphere out of cast sulfur. (You can melt it like plastic, but it stinks.) He mounted this ball on a shaft with a crank handle, and what you did was turn the crank while keeping one hand rubbing against the sphere. On cool, dry days, this would charge you (and the sphere) with static electricity.

Newton improved on it. Winter improved on that. Pretty soon everyone and their dog was making an electrostatic generator. The most advanced is probably the Van de Graaff Generator of 1929, where a belt scuffs against rollers, carrying high charge up to a spherical ball on top. You’ve probably seen one of these at least once on TV.

There are obvious ones and there are not-so-obvious ones. Perhaps one of the most difficult to understand is the Wimshurst Machine. Two counter-rotating plates have conductive patches on them with cross-spanning wires that lure the patches into polarizing while connected, then spin them into position where like charge is pushing against itself so hard that it jumps off the patches entirely. There is a vaguely similar device called a “dirod,” too.

Or just as peculiar is the Kelvin Water Dropper, where water falling out of two holes in a bucket is polarized by the presence of two wires connected to charged metal cans beneath, but tricked into falling into the wrong bucket, adding to their charges instead of reducing them. This is not exactly how thunderclouds charge up, but we don’t know for certain exactly how they charge themselves.

Your mission is to find an ELECTROSTATIC GENERATOR described online, in a book, in a video, or wherever, tell me in Canvas which one you picked, and why you like it (or hate it, if applicable). That’s all I want. Type it in as a Text Entry.

Now even I am not so dense that if you all pick the same exact one from the same exact source, my eyebrow won’t be raised. I’m not asking you to build anything. Just read about one of these devices or watch a video on it. There are so very many, and countless variants of each one. There are people who build these as a hobby and post their work on YouTube. There are collectors and museums and on and on and on.

Have fun!

Lab 3: Capacitors in Series and in Parallel If you have not already done so, please be sure to read the “Introduction to Capacitor Circuits”. Part 1: Single Capacitor You are given the following data (measured charge and voltage) for a capacitor that has been wired to a voltage source. Voltage (Volts) 1.5 3.0 4.5 6.0 7.5 9.0 Charge (microCoulombs) 33.66 68.64 97.02 128.0 166.7 198.0 1. Create a graph with charge (in Coulombs) on the y-axis and voltage on the x-axis. Then use the slope of the graph to determine the value of the capacitor. Include a screenshot of your graph. Excel note: after you get the trendline for your graph, and the equation for the trendline, right click on the trendline equation, and then click on Format Trendline Label. In the category, change this to “scientific” and display 3 decimal places. You will want to follow these steps throughout this lab with each graph. 2. The theoretical value of this capacitor, as read from its’ packaging, is 22 microCoulombs. Calculate the percent error. Lab 3: Capacitors in Series and in Parallel Part 2: Parallel Capacitor Circuit Now, you have a circuit with two capacitors, connected in parallel to a voltage source. For each, you measure the applied voltage, and the charge on each capacitor when fully charged, resulting in the measurements below: Voltage on Capacitor 1 (Volts) 1.5 3.0 4.5 6.0 7.5 9.0 Charge on Capacitor 1 (microCoulombs) 36.3 74.1 106 136 187 220 Voltage on Capacitor 2 (Volts) 1.5 3.0 4.5 6.0 7.5 9.0 Charge on Capacitor 2 (microCoulombs) 77.0 128 211 290 367 449 3. For capacitor 1, create a graph with charge (in Coulombs) on the y-axis and voltage on the xaxis. Then use the slope of the graph to determine the value of the capacitor. Include a screenshot of your graph. Lab 3: Capacitors in Series and in Parallel 4. For capacitor 2, create a graph with charge (in Coulombs) on the y-axis and voltage on the xaxis. Then use the slope of the graph to determine the value of the capacitor. Include a screenshot of your graph. 5. Next, create a data table for the equivalent circuit, with the total voltage and the total charge that correspond to those voltages. Total Voltage (Volts) Total Charge (Coulombs) 6. Create a graph with charge (in Coulombs) on the y-axis and voltage on the x-axis. Then use the slope of the graph to determine the value of the capacitor. Include a screenshot of your graph. Lab 3: Capacitors in Series and in Parallel 7. For a parallel circuit, how do we calculate the equivalent capacitance? 8. Using the values of capacitance that you found from the graphs of capacitor 1 and capacitor 2 above, what would the equivalent capacitance be? 9. When you have capacitors in parallel, is the parallel capacitance always greater, similar to, or less than the values on the individual capacitors? Part 3: Series Capacitor Circuit Now, you have a circuit with two capacitors, connected in series to a voltage source. For each, you measure the applied voltage, and the charge on each capacitor when fully charged, resulting in the measurements below: Voltage on Capacitor 1 (Volts) 0.55 1.04 1.67 2.16 2.56 3.21 Charge on Capacitor 1 (microCoulombs) 47.2 94.5 142 189 236 283 Voltage on Capacitor 2 (Volts) 0.98 2.03 2.81 3.82 4.83 5.91 Charge on Capacitor 2 (microCoulombs) 47.2 94.5 142 189 236 283 10. For capacitor 1, create a graph with charge (in Coulombs) on the y-axis and voltage on the xaxis. Then use the slope of the graph to determine the value of the capacitor. Include a screenshot of your graph. Lab 3: Capacitors in Series and in Parallel 11. For capacitor 2, create a graph with charge (in Coulombs) on the y-axis and voltage on the xaxis. Then use the slope of the graph to determine the value of the capacitor. Include a screenshot of your graph. 12. Next, create a data table for the equivalent circuit, with the total voltage and the total charge that correspond to those voltages. Total Voltage (Volts) Total Charge (Coulombs) 13. Create a graph with charge (in Coulombs) on the y-axis and voltage on the x-axis. Then use the slope of the graph to determine the value of the capacitor. Include a screenshot of your graph. Lab 3: Capacitors in Series and in Parallel 14. For a series circuit, how do we calculate the equivalent capacitance? 15. Using the values of capacitance that you found from the graphs of capacitor 1 and capacitor 2 above, what would the equivalent capacitance be? 16. When you have capacitors in series, is the parallel capacitance always greater, similar to, or less than the values on the individual capacitors? Part 4: Mystery Capacitor The multimeters that we have in the lab are only able to read capacitance values that are less than or equal to 100 microFarads. We have two capacitors that we tried to measure the capacitance of, and they were too large for our meters. 17. Should we wire these capacitors in series, or in parallel, in order to be able to do measurements to figure out the capacitance of each? Explain why. For this, we will do just one measurement, and do a calculation based on the values rather than using slopes. Using the multimeter, we measured the voltages on both of the capacitors, and the equivalent capacitance for the two mystery capacitors, now wired in series. Total voltage supplied by battery Equivalent capacitance measured by meter 6.00 volts 73.3 microFarads 18. Based on these values, calculate the total charge on each capacitor. Show your work. Lab 3: Capacitors in Series and in Parallel 19. What is the charge on each capacitor? Now, you measure the voltage on each of the two capacitors: Voltage on capacitor 1 Voltage on capacitor 2 4.00 Volts 2.00 Volts 20. Calculate the capacitance for capacitor 1. Show your work. 21. Calculate the capacitance for capacitor 2. Show your work.

Pre-Laboratory Work (estimated time 45 mins) Part I: Problem 1. Consider a cart moving along an incline of angle  with respect to the horizontal plane. a. Suppose you give an initial push to the cart that starts at the bottom of the incline. Your push is in the upward direction along the track. Assume that the incline and the cart are frictionless. Describe the motion of the cart right after the push. b. Is the velocity of the cart constant? Is the acceleration constant? c. The diagram below shows the cart (represented by a box) at initial time (t0) and final time (t3) (the cart is moving from the bottom to the top of the incline). Draw the position of the cart at times t1 and t2, such that the time intervals (t1-t0), (t1-t2) and (t3-t2) are all equal. Also, indicate the velocity and acceleration vectors at each of the four time instants (t0, t1, t2, and t3) in the figure below. d. Suppose that the distance between the initial and the final positions drawn on the previous figure is 0.8 𝑚, the initial velocity of the cart is 0.5 𝑚/𝑠, and (𝑡3 − 𝑡0 ) = 1.3 𝑠. Find the value of 𝑎. Show your work explicitly. e. Find the velocity of the cart when it reaches the final position (at 𝑡3 ). f. Does the acceleration depend on the angle of inclination of the track? If so, how? Date Modified: 04/18/19 Project I Lab 1 – Kinematics Page 1 g. What do you think are the initial experimental conditions that affect the motion of the cart? List them below. Part II: Discretization of the kinematic equations: a. Watch the video “Project 1 video 1” that you can find in E-learning. b. Write down the equation for the numerical evaluation of the derivative of the velocity with respect to time as explained in the video. End of Pre-Laboratory Work Date Modified: 04/18/19 Project I Lab 1 – Kinematics Page 2 Auto Run #1 Run #1 Run #1 Run #1 Position Angle of Incline Time (s) Speed (m/s) Speed (m/s) Speed (m/s) Speed (m/s) (m) 3 degrees 2,477 0,66 0 2,922 0,54 0,3 3,428 0,47 0,6 4,186 0,29 Time (s) Speed (m/s) Acceleration 2,477 0,66 0,26 2,922 0,54 0,28 3,428 0,47 0,13 4,186 0,29 0,06

Name: Lab partners: Physics For Life Sciences Lab 2: The (highly morbid) Skeleton Vector Lab. Overview: ​Most people don’t know that the human body is just one huge collection of vectors. Some of these are position vectors, some are force vectors, and some are torque vectors. The relationship between these vectors determines things like whether or not you can lift a piece of furniture without throwing your back out. People who study physical therapy and medicine are especially in tune with how the balancing of these vectors determines physical health and good functioning of the body. In this lab, we will begin the process of seeing the parts that make human (and animal) bodies can actually be described as vectors. Part 1: The human body At the end of this lab, you will find a picture of skeletons posing. For this picture, find the Humerus, Radius, Femur, Tibia (both left and right sides). Treat each bone as a vector beginning at one joint and ending at the other (you can choose, but be careful about negative signs). Then find the x and y components of each bone vector in units of centimeters using a ruler. Once you have the components, express each vector in (i,j) notation. Lastly, once you have each bone in vector notation, find the magnitude and direction of each bone vector. You will have a total of eight vectors that you will submit, along with your notes and calculations. Part 2: The Animal Body Now you will go online and find the skeleton of your favorite animal. Could be a horse, dog, cat, dinosaur, etc. Then print out a picture of its skeleton and repeat the process from Part 1 for that animal skeleton finding the position vectors for any four bones. If you simply do not have a favorite, I included the picture of a dinosaur skeleton which you may use. Deliverables: ​At the end of this lab, each person will submit all their professional work and final vectors for both the skeleton and custom animal in one .pdf file. 1 2 3

Name Rifle Shots-Time to Hit Ground 46 The eight figures below show rifles that are being fired horizontally, i.c., straight out, off platforms. The bullets fired from the rifles are all identical, but the rifles propel the bullets at different speeds. The specific speed of each bullet and the height of each platform is given. All of the bullets miss the targets and hit the ground. Rank these bullets, from longest to shortest, on the basis of how long it takes a bullet to hit the ground. That is, put first the bullet that will take the longest time from being fired to hitting the ground, and put last the bullet that will take the shortest time. Scratch Work: 5 m/s 8 m/s 8 m/s 12 m/s 1 30 m 40 m 40’m 20’m A D B С 5 m/s 12 m/s 10 m/s 8 m/s 20 m 20’m 30 m 30 m E F G н Shortest Longest 1 2 3 4 5 6 7 8 Or, all of the bullets reach ground at the same time. Please carefully explain your reasoning and/or the equation you used for your answers. How sure were you of your ranking? (Type answer below) Basically Guessed Sure 1 2 3 4 5 6 7 8 Very Sure 9 10 46 D. Maloney Physics Ranking Tasks 49 Mechanics