In tennis, ball speed refers to how fast the ball travels through the air after being hit by a player. It is typically measured in miles per hour (mph) or kilometers per hour (km/h). Professional players can hit serves with speeds exceeding 130 mph (210 km/h), while groundstrokes usually range between 60-80 mph (95-130 km/h). Faster ball speeds make it more challenging for opponents t... https://letsgotennis.com/tennis-guide/tennis-power-vs-speed/