What is the period of the wave motion for a wave with a frequency of 0.15 kHz? A sound wave has a frequency of 1996 Hz. What is the distance in meters between crests or compressions of the wave? (Take the speed of sound to be 344 m/s.) Waves moving on a lake have a speed of 1.4 m/s and a distance of 1.2 m between adjacent crests. (a) What is the frequency of the waves? Hz (b) Find the period of the wave motion. s