Question

Draw Conclusions At point \(A\) an echo, a sound wave bounced off the ocean floor, took 2 s to reach the ship. It took \(2.4 \mathrm{~s}\) at point B. Which point is deeper?

Short answer

Point B is deeper than point A.

Step-by-step solution

Analyze the Echo Time

The time it takes for an echo to return to the ship is the total time for the sound wave to travel to the ocean floor and back. At point A, it takes 2 seconds, while at point B it takes 2.4 seconds.

Understand the Relation Between Time and Depth

The sound wave travels the same speed in water, so a longer echo time means the wave traveled a longer distance. This implies the deeper the ocean, the longer the echo takes.

Compare Time to Determine Depths

Since point B has a longer echo return time (2.4 s) compared to point A (2 s), the ocean at point B must be deeper. The additional time indicates the sound wave traveled a greater distance.

Key concepts

Echo

An echo is a reflection of sound that arrives at the listener sometime after the sound was originally produced. This phenomenon occurs due to the bouncing of sound waves against a surface. In the context of ocean exploration, echoes are essential tools for measuring the depth of the water. The time difference between the emission of the sound wave and its return to its original source measures how far the wave traveled. This time delay is crucial in calculating the distance to objects such as the ocean floor, allowing scientists to map underwater topography accurately.

When sound travels through water, it moves in a straight path until it hits an obstacle like the ocean floor. The sound then bounces back, or echoes, which is picked up by sensors. By measuring the time taken for the echo to return, we can infer details about the distant object or surface, such as how far away it is.

Ocean Depth

The depth of the ocean is an intriguing and vital scientific measurement that varies significantly across the ocean itself. Knowing the depth at different points can help in navigation, marine biology, and geological studies. A very popular method to measure the depth is by using sound waves, as done in our exercise.

In the exercise, the later returning echo at point B indicates a greater ocean depth compared to point A. As sound travels at a known speed in water, the longer travel time to and from the bottom is proportional to greater depth.

• Sound waves travel down to the ocean floor and are reflected back to the source.
• The time taken for this round trip is crucial in calculating depth.

These measurements are vital for understanding oceanic structures and ensuring safe and efficient maritime travel.

Wave Speed

Wave speed is a fundamental property of sound waves that determines how fast the wave travels through a given medium. In our context, the speed of sound in water is approximately 1500 meters per second, although it can vary slightly based on temperature, salinity, and pressure.

Since wave speed is relatively constant in water, the time difference in our exercise directly relates to differing distances traveled by sound waves to points A and B in the ocean. The wave speed helps in calculating the precise depth by using the formula:
\[ \text{Distance} = \text{Speed} \times \text{Time} \]
Here, knowing the speed and the time taken by the wave helps in solving for the distance, thus giving the depth of the ocean at each point. This relationship is critical in various applications like oceanography and seismic studies.

Science Education

Science education encompasses a thorough understanding of natural phenomena such as sound waves and their applications in real-world scenarios. Learning about sound waves and their use in measuring ocean depth teaches students valuable skills in critical thinking and problem-solving.

This exercise is a classic example of how basic scientific principles like wave behavior can have practical applications, such as using echoes to measure ocean depths. It demonstrates the interconnectedness of scientific disciplines and practical use in fields like marine navigation and environmental studies.

• Students learn to draw conclusions based on data.
• Understanding these concepts builds a foundation for further scientific studies.

Scientifically understanding these processes empowers learners to appreciate technology's role in exploring and comprehending our planet's intricate systems.