An echo sounder operates by measuring the time required for a ________.
A. light beam to travel from a satellite at a known altitude to the sea bottom and back
B. radar beam to travel from a harbor patrol boat to a fuzz-buster on a speeding yacht
C. radar beam to travel from a ship to the seafloor and back
D. sound pulse to travel from a ship to the seafloor and back
Answer:D
An echo sounder operates by measuring the time required for a ________.
A. light beam to travel from a satellite at a known altitude to the sea bottom and back B. radar beam to travel from a harbor patrol boat to a fuzz-buster on a speeding yacht C. radar beam to travel from a ship to the seafloor and back D. sound pulse to travel from a ship to the seafloor and back