What is the average wind speed of flatulence?

The average human farts 14 times a day. Farts have been clocked at a speed of 10 feet per second or 6.81818182 mph. Temperature of a fart is 37c

Part of it travels at the speed of sound. Part of it travels at the speed of smell. The former is a function of air temperature and pressure, and is in the neighborhood of 1100 ft/sec. The latter is a function of concentration and air speed. it depends on internal pressure, the tightness of the sphincter, and whether there are any "obstructions" in the lower bowel