Final Exam Project – AP Physics 1

Introduction: For our Final Exam project, you will complete a lab simulation involving springs and Simple Harmonic Motion.  This lab is similar to an activity that we completed in class before SPARC and Spring Break.  You may prepare your lab report electronically (using Word, Excel, etc.) or on a sheet of paper.  Please submit your final lab report as a PDF.  All students must collect their own data.  Your data should not be the same as anyone else.

Objective: Using the PhET simulation “Masses and Springs: Basics”, determine the spring constant of a spring and determine the mass of an unknown material.

1. Begin by loading the simulation from https://phet.colorado.edu/en/simulation/masses-and-springs-basics .  Click on “Lab”, then take a few minutes to explore how the program works.  You can adjust the mass of your “known mass”, adjust the spring constant, hang a mass on the spring so that it oscillates, and make measurements with a ruler and stopwatch.

2. Create a data table to record mass (kg), total time for ten oscillations (s), and period for one oscillation (s) for a total of five trials.

3. Adjust the slider at the top of the lab for “Spring Strength 1”.  Your spring should be different than anyone else in the class.  Once you have set the spring strength, you will not change this for the rest of the lab.  The “Spring Strength” slider is on a scale from “0” (on the left) to “9” (on the right).  Please write in your lab report the number that you chose for your lab.

4. Place the known mass on the spring so that the spring oscillates.  Record the value of the mass in your data table.

5. Using the stopwatch in the program, measure and record the time for ten full oscillations.

6. Divide the total time by ten to get the period for a single oscillation.  Record this in your data table.

7. Stop the spring from oscillating (use the red button), then change the value of the known mass (use the slider at the top left).  Do NOT adjust the value of the spring constant (ie. do NOT move the slider on the top right).  Record the new value for your known mass.

8. Repeat steps 5-7 for a total of five trials.

9. Select any ONE of the unknown masses from the bottom of the simulation and place this on the spring.  Record the color of the unknown mass.  Using the stopwatch in the program, measure and record the time for ten full oscillations with this mass.  Divide the total time by ten to get the period for a single oscillation.  Record this data in your lab report.

Analysis

1. Create a graph of Period² (y-axis) vs. mass (x-axis) for your five trials from your data table.

2. Draw the line of best fit and determine the slope.

3. Using the slope from your graph, calculate the value of “k”, the spring constant.  Include units with your answer.

4. Using the value of “k” that you calculated and the period of oscillation for the unknown mass (step 9 in your procedure), calculate the value of the unknown mass.

Conclusion: Write a full conclusion for this activity in which you discuss your purpose, method, results, errors, and future plans.