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
The Crests charted with their first release, "Sweetest One", on Joyce Records. After recording two more singles for Joyce Records, Patricia Vandross left The Crests in 1958 to finish her education. Their next single after "16 Candles" on COED Records was "Six Nights A Week" which hit #28 on the "Billboard" Hot 100 Charts and #17 on the R&B. Their next release "Flower Of Love" was bland compared to other Crests cuts and attained only a six-week run-up to #79. From 1958 to 1960 the group was almost always on the road. In the late 1950s, The Crests performed on several national