If anyone could help with the following, it would be great. I am currently carrying out an experiment for a school project to see how damping affects and reduces the amplitude of the oscillation of a pendulum. For the pendulum I am using a suspended metre ruler and I will count the number of oscillations before the ruler does not reach a certain amplitude anymore. To vary the level of damping, I am going to attach different surface areas of cardboard to the ruler and then plot a graph of surface area of cardboard (x-axis) verses the oscillation number (y-axis). Having just done this, I get what looks like an exponential decay relationship. Any suggestions or information on why this would be? Thanks.