Grade 10Wave Motion
A submarine is fixed underwater and emits two sound wave pulses into the water in the forward direction and then detects the echoes reflected from a moving object ahead. If the time interval between two emitted pulses is 10 s and the round-trip travel time intervals are 2.0 s and 2.1 s respectively, what is the average speed of the object moving away from the submarine? (Given that the speed of sound wave in water is 1520 ms^-1.) (A) 3.8 ms^-1 (B) 7.6 m s^-1(C) 15 m s^-1 (D) 23 m s^-1
A submarine is fixed underwater and emits two sound wave pulses into the water in the forward direction and then detects the echoes reflected from a moving object ahead. If the time interval between two emitted pulses is 10 s and the round-trip travel time intervals are 2.0 s and 2.1 s respectively, what is the average speed of the object moving away from the submarine? (Given that the speed of sound wave in water is 1520 ms^-1.)
(A) 3.8 ms^-1 (B) 7.6 m s^-1
(C) 15 m s^-1 (D) 23 m s^-1
