Which statement make the correctly describes both sound and light waves

What are two different ways you could find the value of a? explain these methods.

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?

Atoms in a molecule are bonded together by sharing gaining or losing_