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  • Periodic Motion
  • Simple Harmonic Motion
  • Conservation of Energy
  • Period
  • Pendulum


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, the strength of gravity, and the amplitude of the swing. Observe the energy in the system in real-time, and vary the amount of friction. Measure the period using the stopwatch or period timer. Use the pendulum to find the value of g on Planet X. Notice the anharmonic behavior at large amplitude.

Sample Learning Goals

  • Design experiments to determine which variables affect the period of a pendulum
  • Quantitatively describe how the period of a pendulum depends on these variables
  • Explain the small-angle approximation, and define what constitutes a “small” angle
  • Determine the gravitational acceleration of Planet X
  • Explain the conservation of mechanical energy, using kinetic energy and gravitational potential energy
  • Describe the Energy Graph from the position and speed of the pendulum
To play simulation click below:
License:[Source phet ]April 30, 2019, 8:53 p.m.