Workout: The pendulum

Read

The pendulum and the example pages, Oscillator graphs and Oscillator calculations

Launch

the PhET simulation Pendulum lab.

Set up

Make sure that the length is set to 2 m, the mass to 1 kg, and friction to 0. Click the boxes to turn on the display of velocity vector and energies for the mass. Your screen should look like the figure at the right.

Answer these questions

1. Describe what happens to the KE/PE and the velocity arrow as it goes through a cycle. Is this correctly displaying what's happening physically?

 2. Now turn on the acceleration arrow. Describe what it does as you go through a cycle. Is it doing what you expect? Explain why it is not 0 at the bottom of the swing.

Joe Redish, spring 2017