[单选题]
A light and a heavy spring are attache
hkjqu( 5ex g*;) jleh-d a
.2 s1/(kovhigyl/klv t point $Y$. A pulse was generated in the light spring and incident on the heavy spring. The positions of transmitted and reflected pulses after some time are as shown.
Which of the following is true about the incident pulse?
A. Positive displacement Positive displacement ;Larger amplitude than reflected pulse
B. Positive displacement;Smaller amplitude than reflected pulse
C. Negative displacement;Larger amplitude than reflected pulse
D. Negative displacement;Smaller amplitude than reflected pulse
参考答案:
C
本题详细解析:
Explanation:
The energy of the incident pulse is shared with reflected and transmitted pulses. Therefore, the amplitude of the incident pulse should be greater than the one of the reflected pulse. Pulses are inverted after reflection from the heavy boundaries. Hence, the incident pulse should have a negative displacement. Therefore the answer is C.
