Exam (elaborations) GIZMOS Student Exploration Period Of A Pendulum

Exam (elaborations) GIZMOS Student Exploration Period Of A Pendulum Vocabulary: controlled experiment, mean, pendulum, period Federalism, mode of political organization that unites separate states or other polities within an overarching political system in a way that allows each to maintain its own integrity. Federal systems do this by requiring that basic policies be made and implemented through negotiation in some form, so that all the members can share in making and executing decisions. Prior Knowledge Questions (Do these BEFORE using the Gizmo.) A pendulum is a weight that can swing freely back and forth. The period of a pendulum is the amount of time required to make one full back-and-forth swing. In each of the comparisons below, circle the pendulum that you think will have a shorter period. Long pendulum vs. Short pendulum Heavy pendulum vs. Light pendulum Pendulum on Earth vs. Pendulum on Moon Pendulum with a large arc vs. Pendulum with a small arc Gizmo Warm-up The Period of a Pendulum Gizmo™ allows you to explore the factors that control how quickly a pendulum swings back and forth. To begin, practice measuring the period of the pendulum. On the Gizmo, check that all variables are set to their original values: m = 0.5 kg, L = 2.0 m, g = 9.8 m/s 2 , and θ = 20°. Open the Tools tab and drag an arrow so that it just touches the pendulum at its left-most position, as shown at right. 1. A full “swing” of the pendulum is one complete back-and-forth movement. Select the TABLE tab. Click Mark time each time the pendulum touches the arrow. Mark 10 times. What values do you get for the period of the pendulum? ___1.14___ ___1.56___ __2.03____ _2.90____ _3.16_____ __3.46____ __4.17____ __5.21____ __6.95____ __7.56____ GIZMOS Student Exploration Period of a Pendulum 2. What is the mean of these values? (Note: To find the mean, add up the values and divide by the number of values, or 10.) _____3.814 ___________ Introduction: The Period of a Pendulum Gizmo allows you to investigate four factors: mass (m), length (L), gravitational acceleration (g), and angle (θ). Question: Which factors affect the period of a pendulum? 1. Measure: Click Mark time. Carefully count 10 swings of the pendulum, and click Mark time again at the conclusion of the last swing. A. What is the time for 10 swings? __10.30__________ B. Divide the time by 10. What is the measured period of the pendulum? ____1.03 _ C. How does this value compare to the mean period you found in the Gizmo Warm-up? ____I calculated the wrong thing. I kept hitting mark time each time I calculated the swing. For 10 swings in one mark time it is pretty short _________________ 2. Design an experiment: To conduct a fair test of the factors that could affect the period of a pendulum, change only one factor at a time. This is known as a controlled experiment. First, design a controlled experiment to find the effect of mass (m) on period. Describe your experiment below. _________________________________________________________________________ _________________________________________________________________________ 2. Gather data: Record the results of your experiment in the table below. 3. Analyze: What was the effect of pendulum mass on the period of the pendulum? __Mass does not affect the pendulum's swing. The longer the length of string, the farther the pendulum falls; and therefore, the longer the period, or back and forth swing of the pendulum_______ Activity A: Factors affecting period Get the Gizmo ready: ● On the TABLE tab, click Reset. m (kg) L (m) g (m/s 2 ) θ (°) Time for 10 swings (s) Period (s) 0.1 2.0 9.8 20 10.73 1.1 0.5 1.5 9.8 20 10.33 1.03 1.0 2.0 20.5 20 8.16 0.85 (Activity A continued on next page) Activity A (continued from previous page) 4. Investigate: Conduct similar controlled experiments on the effects of length, gravitational acceleration, and angle on the pendulum period. Record your results below. Length experiment Gravitation experiment Angle experiment 5. Analyze: Look at your data. A. How did changing the length (L) affect the period? _______It reduced the speed of the pendulum when the length is reduced.____________________ ___________________________________________________________________ B. How did changing the gravitational acceleration (g) affect the period? ___The increase in the acceleration made the pendulum swing faster_________ ___________________________________________________________________ C. How did changing the initial angle (θ) affect the period? __The pendulum swing was not slow or fast but it increased the time of a normal swing 10 times._____________________ ___________________________________________________________________ 6. Compare: How did the results of your experiments compare to the predictions you made in the Prior Knowledge Questions? _______________________________________________