The chart shows data for four heat engines
which lists the engines from most efficient to least efficient?
y, x, w, z
z, w, x, y
z, x, w, y
oy, w, x, z

An important dimensionless parameter concerned with very high-speed flow is the mach number, defined as v/c, where v is the speed of the object such as an airplane or projectile, and c is the speed of sound in the fluid surrounding the object. for a projectile traveling at 1170 mph through air at 50 ˚f and standard atmospheric pressure, what is the value of the mach number?