In a stringed musical instrument, the part that vibrates in resonance with the sound waves produced by the strings is called the
A. diatonic scale.
b. reed.
C. membrane.
D. sounding board.
If a wave hits a smooth surface at an angle of incidence of 40 degrees, the angle of reflection is
a. 80 degrees.
B. 40 degrees.
C. 90 degrees.
D. 0 degrees.