What is the speed of sound used in calculations by observers?

The speed of sound used in calculations by observers is typically taken to be around 350 meters per second. This value is a standard approximation in many military and aviation contexts, as it represents the average speed of sound at sea level and at a temperature of about 20 degrees Celsius. The speed of sound can fluctuate based on various factors such as altitude, air temperature, and humidity, but 350 meters per second provides a reliable baseline for calculations involving fire support and other operations where accurate targeting and timing are critical. Observers use this figure to help determine factors like the time it takes for sound to travel from a source to their location, which is essential for coordinating fire support efforts effectively.