The speed of highly penetrating ultrasonic waves is:
A. lower than those of audible sound waves
B. higher than those of audible sound waves
C. much higher than those of audible sound waves
D. same as those of audible sound waves
Answer:D
The speed of highly penetrating ultrasonic waves is:
A. lower than those of audible sound waves B. higher than those of audible sound waves C. much higher than those of audible sound waves D. same as those of audible sound waves