A The position of the mass is periodic, or harmonic, in time, i.e. it repeats. Notice it oscillates between +A and A, the amplitude, and the motion repeats continuously in the absence of friction. Let"s define a few quantities that we will use to characterize the SHM. Period: The time it takes to complete 1 cycle, T. Units? [s] Frequency: # of complete cycles per unit time, f. Units? Example: What is the amplitude, period, and frequency of the following motion? Period?