試題詳解

53. Two strings of different linear mass density are joined at x = 0 to form a new string. The heavier string and the lighter string are on the left and right hand side of x = 0, respectively. Now, we keep the string stretched with a fixed weight, and send a wave from the heavier end to the lighter end. Which of the following statements is correct?
(A) As the wave travels to the lighter end, its profile is amplified.
(B) As the wave travels to the lighter end, its speed decreases.
(C) As the wave hits x = 0, the reflected wave travels faster in the heavier string.
(D) The speed of the traveling wave remains the same regardless of which ends.
(E) As the wave hits x = 0, there is no reflected wave.