Submarines use a technology called "sonar" that bounces sound waves off of objects in the water. The sonar operators measure how long it takes for the signal to return to them. The information they get from sonar allows them to know
A.
how massive objects in the water are
B.
how far away objects in the water are
C.
if objects in the water are man-made
D.
what color objects in the water are
1 answer
B. how far away objects in the water are
4 answers