40. A block with a speaker bolted to it ..-阿摩線上測驗
40. A block with a speaker bolted to it is connected to a spring having spring constant k = 20
N / m
as shown in figure. The total mass of the block and speaker is 5 kg, and the amplitude of this
unit’s motion is 0.5 m. The speaker emits sound waves of frequency 440 Hz. Determine the
highest frequency heard by the person to the right of the speaker. (Assume that the speed of sound
is 343
ms)
(A) 481 Hz
(B) 471 Hz
(C) 461 Hz
(D) 451 Hz
(E) 441 Hz