The table shows the speed of sound in different materials.
Material
sea water
air at 20°C
Speed of
sound (m/s)
1533
343
1 Earth scientists have maps that show the shape of the bottom of the oceans. The Atlantic Ocean
has a ridge down the middle. The top of the ridge is approximately 2000 m below the surface of
the water.
a What is the total distance travelled by a sonar pulse that goes from the surface to the ridge and
is reflected back to the surface again?

b Calculate the time it would take a sonar pulse to travel this distance in sea water.