To determine if an object is moving faster than the speed of sound, you can use a few different methods:
Sonic Boom: When an object moves faster than the speed of sound (also called supersonic speed), it creates a shock wave known as a sonic boom. A sonic boom is a loud noise caused by the sudden pressure change in the air as the object moves through it. If you hear a loud boom or a double boom, it suggests that the object is traveling at supersonic speeds.
Mach Number: The Mach number is a dimensionless quantity that compares the speed of an object to the speed of sound in the surrounding medium. It is defined as the ratio of the object's velocity to the speed of sound. If the Mach number is greater than 1, the object is traveling faster than sound. For example, Mach 1 corresponds to the speed of sound, Mach 2 corresponds to twice the speed of sound, and so on.
Observational Cues: Visual cues can also indicate whether an object is moving faster than sound. If you see an object before you hear it, it suggests that the object is traveling faster than the speed of sound. This is because light travels much faster than sound, so the object can reach your eyes before the sound waves can reach your ears.
Vapor Cone or Prandtl-Glauert Singularity: When an object moves through the air at supersonic speeds, it can sometimes create a visible vapor cone or a condensation cloud. This occurs due to the drop in air pressure and temperature as the air is rapidly compressed and then expanded behind the object. The vapor cone is a visual indication that the object is moving faster than sound.
It's worth noting that the speed of sound varies with different factors such as altitude, temperature, and humidity. At sea level and room temperature (around 20 degrees Celsius or 68 degrees Fahrenheit), the speed of sound is approximately 343 meters per second or 1,125 feet per second.