Lab 2 Velocity & Acceleration QMPHYS1115 Rev8.24.2023

Lab 2: Velocity & Acceleration © 2023 by Orlando Patricio & Alfonso Hinojosa adapted from Physics Lab Manual Name: Alexandra Chapa INSTRUCTIONS: (1) Download this lab document, CLICK on “ enable editing ” located at the top, middle of the downloaded document and type out answers on the space provided for then save your answers. (2) If the spacing automatically moves, adjust so that your answers are not all over the place. (3) Upload this document, with your answers on it, on the designated Lab 2 Dropbox on Canvas Lab Reports/Module Tab. (4) If possible, ALL answers must be in green font or highlighted in yellow background with black font . Safety Before conducting any lab activity in this course, LC students are required to read the Flinn Lab Safety Procedure/Contract (posted on Canvas Modules Tab: Module 1) and watch the online Flinn Safety Video. To watch the safety video now, click on Flinn Lab Safety Video link in Module 1 or hover mouse on the link below and press at the same time ctrl and left click this link: https://www.youtube.com/watch?v=HLaOJKD9iDg . Remember to take Lab Quiz 1 (Lab Safety) on Canvas (use Lockdown Browser and Webcam). Grading Policy for Lab Reports WITH Pre-/Post-lab Questions Grading Policy for Lab Reports WITHOUT Pre-/Post-lab Questions Completeness and accuracy of answers (with required screenshots) for the: 1. Warm-up and lab activities – 70% 2. Pre-/Post-lab questions – 10% 3. Conclusions and real-life applications – 20% Completeness and accuracy of answers (with required screenshots) for the: 1. Warm-up and lab activities – 80% 2. Conclusions & real-life applications – 20% Part 1: Constant Velocity (or Constant Speed) Purposes/Objectives: In this lab, (1) you will record the distance, x (in meters) and time, t (in seconds) for several 1-m intervals as a walker travels at a constant velocity on a level pavement in your backyard or on a level road in front of your house. (2) you will plot graphs of distance vs. time for three walkers (or one walker doing it three times) and relate the slope of each distance vs. time graph to the (average) speed of the walker. Materials : Each lab group (student + assistant or a member of your family) will need the following: computer, metric ruler or measuring tape and cellphone stopwatch.

Procedure: Using masking tape (or colored chalk or small rocks or crumpled papers), mark out a level pavement 10 m linear distance for you to walk in while making a 1-meter division marks. Note: If you don’t have a meterstick, use a ruler: 1 m = approximately 3 and ¼ of a ruler. Another way to approximate 1 m: stretch your right arm horizontally and measure the distance up to a little more to your opposite shoulder. Set up your stopwatch so that you can begin to measure time as soon as you start walking. Safety Note: Perform this experiment in a safe place, free from obstructions and vehicles. As a group, complete the following steps: 1) In your group, decide your goal speed (in units of meters per second, m/s). For example, your speed could be, on average, 1 m/s or 2 m/s. 2) While recording your data, each member (or one walker will do three trials) of the group should attempt their walking speed a few times. Trying to walk in SI units is not necessarily intuitive! 3) For each of these group members, they should start from one end of the distance you marked off as zero-meter, walking at their speed towards the other end. Measure and record each time interval by laps. For example, lap 1 for 0-1 m, lap 2 for 1-2 m, lap 3 for 2-3 m, etc. Record the time (in seconds) from 0 to 1 m, from 0 to 2 m, from 0 to 3 m, from 0 to 4 m,…, from 0 to 10 m. [. . . . . . . . . . . ] [0m 1m 2m 3m 4m 5m 6m 7m 8m 9m 10m ] 4) Calculate the average velocity (or average speed) for each of these walkers and compare those to their goal speeds. Were they accurate? 5) If the average velocity (or average speed) was close to the goal speed , someone gives them a high-five! That is an indication of accuracy. 6) Using Excel spreadsheet, create a distance vs. time graph for each walker. To create an Excel graph: (a) open an Excel spreadsheet, (b) type in the cells, time (sec) for the first column and distance (m) for the second column and the corresponding data points, (c) highlight all entries (data points and the title headings such as time and distance), (d) click Insert (next to Home button) then click on Scatter (X, Y) or Bubble Chart located above Charts at the middle top of the control panels or tools (to locate, hover mouse over the dots with arrow pointed down), (e) on the drop-down menu that appears, click on the first selection

(n) click the inside part of the graph (not the dots neither the line) then right click and select copy , (o) open this lab document and paste the graph(s) after the Data Tables (of Part 1) of this lab document, (p) on each distance vs. time graph (on this lab document), label each for Walker 1, Walker 2, and Walker 3, (r) edit all entries as needed. See sample data table and graph after the Conclusions . For all Lab Reports including Data Tables and Graphs, use Times New Roman (or Calibri Font 11 or 12) and Font 12 (preferably 1-inch margin in all four sides). 7) Always remember this: graphs must have correct titles and labels for the x and y axes. Getting comfortable with the equipment Walk briskly/slowly and record the time for every 1-m you traverse. Record your observations during the trials. Observations are listed below.

Data Table Part 1: Constant Velocity (or Constant Speed) Walker 1 Walker 2 Walker 3 ? (s) 𝑥 (m) ? (s) 𝑥 (m) ? (s) 𝑥 (m) 1 0.35 1 1 0.36 1 1 0.38 1 2 0.65 2 2 0.67 2 2 0.69 2 3 1.04 3 3 1.03 3 3 1.08 3 4 1.37 4 4 1.36 4 4 1.38 4 5 1.73 5 5 1.70 5 5 1.72 5 6 2.04 6 6 2.05 6 6 2.05 6 7 2.41 7 7 2.41 7 7 2.42 7 8 2.72 8 8 2.70 8 8 2.74 8 9 2.97 9 9 2.98 9 9 2.99 9 10 3.35 10 10 3.30 10 10 3.36 10 Distance vs. Time Graph for Walker 1: Provided below. 12 10 8 6 4 2 0 0 0.5 1 1.5 2 2.5 3 3.5 4

Parameter Walker 1 or Trial 1 for Walker 1 (m/s) Walker 2 or Trial 2 for Walker 1 (m/s) Walker 3 or Trial 3 for Walker 1 (m/s) Average speed = (total distance / total time) v = x / t = slope of graph 2.9641 m/s 2.9741 m/s 2.9442 m/s Goal speed 3 m/s 3 m/s 3 m/s Accurate? (highlight answer) Yes Yes Yes Part 2: Constant Acceleration or Free-fall Acceleration Purpose/Objective: In the second part of this lab, (1) you will explore if the constant acceleration model accurately describes the motion of a falling object. (2) you will find out if mass affect free-fall acceleration (that is, if air resistance effect is negligible). Materials & Procedure: Using some objects (such as ball, pencil, or crumpled paper, etc.) unlikely to break when dropped, complete the following steps: 1) Find a wall that is at least 2-m high from the floor. Mark the 2-m height with a pencil. 2) Hold the object in line with the measured height of 2-m. 3) Release the object from rest, and let it fall until it hits the ground. Your responsibility is to measure/record the total time it takes for the object to strike the ground from the released point. Measure the time of fall accurately. Time of fall for a height of 2-m is approximately 0.64 seconds. If you measure the time that is close to 0.64 seconds, then record that time in the corresponding data table. If you measure the time that is not close to

0.64 seconds, then disregard and redo the experimental trial. 4) As a group, determine the time interval for each object in free fall. 5) Record 3-4 data points (time in sec) for each released object. 6) Repeat this process, record data each time, for up to three objects. As a group, examine the data you collected and determine whether the constant acceleration model accurately describes the motion of the object that you dropped. Data Table Part 2: Constant Acceleration or Free-fall Acceleration

Sample Data Table: Distance vs. Time for Walker 1 Time (sec) Distanc e (m) 0.34 1 0.67 2 1.02 3 1.35 4 1.71 5 2.06 6 2.39 7 2.69 8 2.99 9 3.32 10 Sample Graph: Distance vs. Time Graph ( d vs. t graph ) for Walker 1 0 0.5 1 1.5 2 2.5 3 3.5 0 2 4 6 8 10 12 f(x) = 2.97 x R² = 1 Distance vs. Time Graph Time (s) Distance (m)