I have to do an investogatory project in school and we can choose the topic of our choice. My teacher has suggested an experiment where we could study the damping effect of a pendulum in three different media-air, water and magnetic field. This sounds pretty interesting (and pretty simple) to me, and I would like to try it out. But I don't know which equations to put into use. I suppose one thing I could do is find the time the pendulum takes to stop oscillating in the three different media but that is all thats clicking me right now. Please help me out and give me some ideas. Thanks.