The purpose of this lab was to use knowledge of the physics of centripetal motion to determine the mass of an unknown object. This was done by attaching a weight to one end of a string and the object being massed to the other end, and spinning the weight in a horizontal circle of a fixed radius. Using physics we created an equation that relates the time it takes to complete 30 revolutions to the mass of the object. We were given a range of possible masses that the final unknown object would fall into, and conducted trials to create a calibration curve that would predict the mass of the object after finding a time experimentally.