Tom Serve speed analysis

This ball speed analysis is made with a 30 fps ph video camera by counting the frames fro racquet impact till ball hit back servis line, Basically the approx 26.28 meters or 86.2 feet horizontal-vertical ball flight
Time of travel 0.666 s or approx 17.5 frames
Average ball speed between racquet and servis line 26.28 m/s or 58.79 mph