This question is about waves.
Which statement correctly describes a sound wave compared to a light wave? A. Sound is a longitudinal wave, whereas light is a transverse wave. B. Sound is a transverse wave, whereas light is a longitudinal wave. C. Both sound and light are longitudinal waves. D. Both sound and light are transverse waves.
Describe an experiment to measure the speed of sound in seawater by using an echo-sounder (sonar) on a boat over a seabed of known depth.
The speed of sound in seawater depends on the water temperature.
The graph shows how the speed of sound varies with water temperature.
Use the graph to estimate the speed of sound in seawater at a temperature of 20 ∘C20\ ^\circ\text{C}20 ∘C.
Describe the pattern shown by the graph.
In the polar regions, the ocean surface water is very cold. Near the equator, the surface water is warm. A marine biologist claims: "A sonar pulse travels faster through the warm equatorial surface waters than through the cold polar surface waters."
Do you agree with the biologist? Explain why.
