Technician A says that fractured rods have a unique mating surface and that only the cap that was fractured is the one that will fit that rod. Technician B says that a powdered metal rod is less expensive, lighter, and as strong as a forged rod. Who is correct?
a) technician A
b) technician B
c) both technicians A and B
d) neither technician A nor B

Waves are used in many practical applications to support work, entertainment, and health. one example is the use of ultrasound imaging to safely track the development of a growing fetus. what is a specific example of a practical application of waves in medicine, entertainment, safety, or other fields? provide a brief explanation of how the properties of waves are useful to that application.