Longitudinal wave and seismic P-waves (created by earthquakes and explosions). In longitudinal waves, the displacement of the medium is parallel to the propagation of the wave, and waves can be either straight or round. A wave along the length of a stretched Slinky toy, where the distance between coils increases and decreases, is a good visualization. In the case of longitudinal harmonic sound waves, the frequency and wavelength can be described by the formula where: The quantity "x"/"c" is the time that the wave takes to travel the distance "x". The ordinary frequency ("f") of the wave is given by The wavelength
Live! Go for What You Know of Travers and Thrall bridged the gap between what it calls "dramatic changes" in metal in the late 1970s: Travers emblematized "the blues-rock sound of sixties and seventies metal" whereas Thrall's playing represents the newer wave in metal (represented by Eddie van Halen): "The combining of the two players' solos during this time showed a rare detente between two generations of hard rockers and, although short-lived, it was extremely exciting." The album was produced by Tom Allom, who had worked on the first five Black Sabbath albums as a sound engineer, had produced two albums by The Tourists, and would