Mach number which was also unit-first, and may have influenced the use of the term Mach. In the decade preceding faster-than-sound human flight, aeronautical engineers referred to the speed of sound as "Mach's number", never "Mach 1". Mach number is useful because the fluid behaves in a similar manner at a given Mach number, regardless of other variables. As modeled in the International Standard Atmosphere, dry air at mean sea level, standard temperature of , the speed of sound is . The speed of sound is not a constant; in a gas, it increases as the absolute temperature increases, and since atmospheric
Mach and Daddy Mach and Daddy Peter "Mach" Machore and Martin "Daddy" Machore, better known as Mach and Daddy, are Panamanian duo brothers of Spanish reggae and reggaeton. The first single for which they were recognized, "La Botella" (""The Bottle""), charted throughout Latin America and hit #1 on the "Billboard" chart. Other popular singles included "La Juma" and "El Que Se Fue Pa Barranquilla". The duo's concerts attracted as many as fifty thousand people. They tour and perform throughout Latin America and the U.S. Peter Machore is "Mach" and Martin Machore is "Daddy". They derived their musical muse from their father, singer and