SCIENCE 101 5.4.3 Lab: Simple Harmonic Motion Dry Lab Physics Sem 1 Points Possible: 50

Coronado High School, Henderson SCIENCE 101 5.4.3 Lab: Simple Harmonic Motion Dry Lab Physics Sem 1 Points Possible: 50 Simple Harmonic Motion Materials: · String · Scissors · Slotted hanging masses · Ri ...

Coronado High School, Henderson SCIENCE 101 5.4.3 Lab: Simple Harmonic Motion Dry Lab Physics Sem 1 Points Possible: 50 Simple Harmonic Motion Materials: · String · Scissors · Slotted hanging masses · Ring stand · Ring (4 inch) · Pendulum support · Spring (or Slinky) · Ring clamp (90-degree rod clamps) · Meter stick · Stopwatch · Graph paper · Presentation software Materials for Exploring Further: · Balance · Ballistic pendulum · Collision apparatus Procedure 1. Develop a hypothesis regarding one factor you think might affect the period of a pendulum or an oscillating mass on a spring. Potential factors include the mass, the spring constant, and the length of the pendulum's string. Write down your hypothesis. 2. Design a controlled experiment to test your hypothesis. Take extreme care to keep all factors constant except the variable you are testing. If you plan a pendulum experiment, for example, choose the pendulum's length, and for either experiment, choose the number of oscillations for each time measurement. If you do not have some of the suggested equipment, decide how you could make the measurements using alternative equipment. For example, balls of clay could be substituted for hanging masses, and the pendulum or spring could be attached to a board extending from a bookshelf. If you perform the experiment with a spring, test the greatest mass on the spring to be sure the setup you plan works with the spring extended fully. Your experiment may be set up like the following: 3. When you have completed the plan, carry out your experiment. Record your data in the table below. Record measurements in scientific notation as appropriate. (Note: Dry Lab data below is supplied for an experimental setup using a pendulum.) Run # Mass (kg) Time for 10 oscillations (s) Period (s) 1 0.05 14.22 1.422 2 0.10 14.18 1.418 3 0.15 14.15 1.415 4 0.20 14.28 1.428 5 0.25 14.33 1.433 4. Create two graphs of your data. Both mass and time for 10 oscillations are independent variables, so either can be placed on the x-axis. In the first graph, place mass on the xaxis. On the second graph, place time for 10 oscillations on the x-axis. The period changes as a result of your independent variable, so it is the dependent variable and should be placed on the y-axis for both graphs. 5. Create a lab report to communicate your findings. The report should include a title page, procedure, data table, graphs, and summary. Be sure that your summary analyzes the findings of your experiment as well as the graph of your results, and that it evaluates the effectiveness of your testing methods. Discuss whether your hypothesis was supported by the data you collected, as well as any modifications you would make if you were to perform the experiment again. 6. Share your charts and graphs using presentation software. Take notes on other students' presentations, paying careful attention to any reports that tested hypotheses other than those you tested. Analyze 1. How did the period of the spring or the pendulum that you tested change as the mass increased? 2. If you tested a pendulum, what happens to the period of the pendulum as the length of the string increases? If you tested the spring, what happens to the period of the spring as the spring constant increase? Draw Conclusions 3. Summarize the effect of various factors on the period of the pendulum or the spring that you tested. Explore Further Part 1: Ballistic Pendulum Experiment Using a balance, determine the mass of the ball and basket of the ballistic pendulum. Fire the ballistic pendulum and measure the maximum height the pendulum reaches. Use the conservation of energy (initial KE + initial GPE = final KE + final GPE; KE = ½mv2; GPE = mgh) to calculate the initial speed of the pendulum after the ball has collided with the pendulum basket. Next, use the conservation of momentum (total initial p = total final p; p = mv) to determine the initial speed of the ball before it collided with the pendulum basket. Part 2: Collision Apparatus Experiment Use a collision apparatus to observe initial and final velocities. Calculate the total initial momentum and the total final momentum, (p = mv). Is momentum conserved in your experiment? Why or why not? Part 3: Graphing Oscillation A. Sketch a graph of position versus time for a mass oscillating on a spring. Label the graph with areas of maximum and minimum velocity (vmax, vmin), maximum and minimum net force (Fmax, Fmin), and maximum and minimum acceleration (amax, amin). B. Under your sketch of position versus time, sketch a graph of velocity versus time for the same mass oscillating on a spring. How do the shapes of the two graphs compare? Part 4: Modeling Motion with Technology Develop a way to better model harmonic motion using a different technology. What technology would you use? Why? Be sure to explain what you are testing for.