text: "Supersonic"\n Supersonics, branch of physics dealing with the phenomena arising when the velocity of a solid body exceeds the speed of sound in the medium, usually air, in which it is traveling.  \n              "Ultrasonic"\nUltrasonics, branch of physics dealing with high-frequency sound waves, usually in the range above 20,000 hertz (Hz), that is, above the audible range.