Virtual Simple Harmonic Motion Lab Part 1: The Pendulum Materials: The PhET Pendulum Lab and Excel Procedure: Using one pendulum in the simulator, explore the relationships between the period of the pendulum (using the photogate timer) vs the mass, length, amplitude (amount of angular displacement), and gravitational field (aka gravitational acceleration). Collect data on an excel spreadsheet (we will turn it into graphs together). For each, you must determine if the period is not dependent upon the variable, directly proportional to the variable, inversely proportional to the variable, directly/inversely proportional to the square of the variable, or directly/inversely proportional to the square root of the variable. Note: please only use angular displacements that are 30⁰ or less. Generally, you will want to keep the friction low to zero, but to stop the pendulum, you can briefly set it to high. Questions: 1. When is the velocity the greatest and the least? Why? 2. When is the acceleration the greatest and the least? Why? 3. A pendulum follows the simplest predictable pattern when the angles from the vertical are small. Using the value of the period created with a 5⁰ amplitude, find the percent error for 30⁰, 45⁰ and 90⁰. Part 2: A Mass on a Spring Materials: The Phet Masses & Springs Simulation and Excel Preliminary Activity: Determine the spring constant for the two set springs and for all the settings from soft to hard on the “softness spring 3” slider. Procedure: Using the simulator, determine the relationships between the period (time to go through one full cycle) vs. the amplitude (how far it is displaced from equilibrium), the mass, the gravitational field, and the spring constant. Collect data for each investigation. Questions: 4. Determine the value of the unknown masses using two different methods.