in what circumstance does the speed of a wave alter?
A. when there is a change in the mass
B. when a wave bounces off a surface
C. when the wave comes into contact with a different medium
D. when there is a change in amplitude of a wave
A. when there is a change in the mass
B. when a wave bounces off a surface
C. when the wave comes into contact with a different medium
D. when there is a change in amplitude of a wave