Input (grade 13): These phenomena include: Thin shock layer As Mach numbers increase, the density behind the shock also increases, which corresponds to a decrease in volume behind the shock wave due to conservation of mass.
Output (grade 10): Some of these things include: Thin Shock Layer As the plane goes faster and mach numbers increase, the density behind the shock also goes up. This happens in concert with a decrease in volume behind the shock wave because of the conservation of mass theory.