Reading Apprenticeship Inspired Assignment or Lesson
Reading Apprenticeship Inspired Assignment or Lesson
In this activity, students will be testing an equation we covered in class that governs the relationship between the period of a simple oscillator and the length of a string attached to a bob mass. Students will perform the experiment at home using a link provided. After that, they need to evaluate their work by finding the percentage error between the experimental and theoretical work.
A simple pendulum is one which can be a point mass suspended from a string or rod of negligible mass. The period of such pendulum can be approximated by:
T=2π(√L/g) eq. (1)
Where L is the length of the string attached to the suspended mass and g is the acceleration of gravity.
Students also need to know that this equation is an approximation that work only in the case of small angles. That means, students must not put the system in large oscillation when performing the experiment because that requires more complex treatment, and it is beyond the scope of the activity.
To evaluate their work, students need to find the period for each trial at least five time. In these 5 attempts, the error in the period should be withing 10% margin of error.
Students also need to use SI system of units, that’s L should be in meters and g in m/s2. Period should be measured in units of second. Students must include the units in all of their work.
In this activity, students will use their prior knowledge to plan a strategy for approaching a learning task, take necessary steps to problem solve, reflect on and evaluate results.
Students need to read the assigned text to collect the necessary information about the activity. After that students will use the provided link to solve the problem and collect the necessary data.
After students collect data, they need to find the percentage error between the theoretical and experimental period and evaluate their results.
This activity is an asynchronous module and expected to take between 1-2 hours. Students can upload their work via Canvas within a week. Students will use different masses attached to a string and measure the period using a timer for every mass. Then they need to use eq. (1) to find the expected period and compare it to the experiment. Students also will use one mass and find the period using different strings with different lengths and find the experimental and theoretical period. In all cases, students need to find the percentage error between the experimental and theoretical period.
Students need to read section 12.5: The motion of a pendulum is approximately simple harmonic from College Physics, 2nd edition by Freedman, Ruskell, Kesten, and Tauck. Below are some images that helps students understand the work they need to do. Students will be using PhET simulation available in this link: https://phet.colorado.edu/en/simulation/pendulum-lab
Play with one or two pendulums and discover how the period of a simple pendulum depends on the length of the string, the mass of the pendulum bob, and the amplitude of the swing. It’s easy to measure the period using the photogate timer.
