A boat sends a sonar signal to find out how deep the ocean is. It takes 10 seconds for the
signal to hit the ocean bottom and return to the earth. What is the distance to the bottom of the
ocean if the sonar signal moves at 1700 m/s?

Explanation:

Let ocean is d meter deep

distance travelled by sound = 2d

velocity of sound v = 1700 m/s

time t = distance / velocity

10 = 2d / 1700

d = 10 x 1700 /2

= 8500 m  

the arctic is a region of the planet, north of the arctic circle, and includes the arctic ocean, greenland, baffin island, other smaller northern islands, and the far northern parts of europe, russia (siberia), alaska and canada.