Standing waves can be produced in a string by attaching one end of the string to an oscillator with frequency f and the other end to a weight, which produces a tension T in the string. For a string with a mass density (mass per unit length) given by , the relationship between the tension in the string and the frequency f and wavelength of the standing wave is given by T = ² f². Suppose you set up such a vibrating string, using an oscillator with a fixed frequency. You then measure the tension required for various wavelengths and make a graph with log T on the horizontal axis and log on the vertical axis. The slope of the graph is: