The speed of sound at an elevation of 40,000 feet, where many aircraft fly, is 295 m/s. If an airplane is flying at Mach 0.92 at this altitude, how fast is the airplane traveling in meters per second? 295 m/s

321 m/s

316 m/s

271 m/s

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Diego is trying to lift a piano to the second floor of his house. diego uses a pulley system and gives a big lift to the piano. the piano moves upward, then stops, and then it starts to fall to the ground. which list best describes the forces on the piano in the proper order? a. positive force, balanced force, negative force b. negative force, balanced force, positive force c. positive force, unbalanced force, negative force d. negative force, unbalanced force, positive force