Figure 6-5 Superposition of two waves of different frequencies but identical amplitudes: (a) wave 1 with a period of 1⁄v_1 (b) wave 2 with a period of 1⁄v_2 =(v_2=1.25v_1) (c) combined wave pattern. Note that superposition of V1 and v2 produces a beat pattern with a period of 1⁄∆v where ∆v=|v_1-v_2 |