Types of Breakers

Making Waves Scientific Investigation

Before you begin the scientific investigation below, make sure to download the Making Waves Scientific Investigation Report. As you complete this scientific investigation, fill in any needed information on the report template. If you need more information about each section of the report, please visit the Developmental Module.

This scientific investigation is available below or in a printable version.

Introduction

As waves approach the shore, they slow down as the depth of the water becomes more and more shallow. The crest of the wave does not interact with the bottom and remains moving at the same pace. The more the bottom energy of the wave drags along the surface below, the more the crest tips over. Eventually, the wave breaks in a zone called the surf zone.

Objectives

In this scientific investigation, you will:

• simulate ocean waves and observe how they behave as they approach the shore.

Hypothesis

Using the Procedure and Data Collection section below, read through the procedural information for this scientific investigation. Based on your understanding of the procedure, develop your own hypotheses which describe your expected results. Record these hypotheses in the Hypothesis section of your Making Waves Scientific Investigation Report.

Procedure and Data Collection

Set-Up

1. Slowly add water to the pan until it is about half full. This water will act as ocean water.
2. Slowly pour sand inside one of the 9-inch ends of your pan to make a relatively flat beach. You do not need to use all of the sand; just use enough sand to cover from one side to the other, and so that some of the sand is above the water line.

Observing Fetch

1. Act as a wind generator by blowing gently on the water from the non-beach end of the tank. It may also help to generate waves by blowing through a straw. Experiment with whichever method and wind force enables a gentle, steady flow of wind.
2. As the wind moves the water, use your ruler to measure the fetch, or the distance over which the wind blows across the water, in centimeters. Measure from the point at which the wind originates near the water to the point at which you can no longer feel steady air movement. In the Data section of your Making Waves Scientific Investigation Report, record the following measurement:

• Fetch Length (cm)

In the Data section of your Making Waves Scientific Investigation Report, draw an accurate cross-section (i.e., from the side) illustration of what the ocean water looks like. Label the following elements:

• Capillary waves
• Chop
• Swell

Observing Progressive Waves

1. Have your partner begin to generate waves by steadily moving the piece of cardboard up and down at the non-beach end of the tank. Start slowly and experiment with the best way to produce waves. Strive for waves that are even and rhythmic.
2. Once the waves are consistent, look at the sides of the tank. Use a ruler to determine the wavelength and wave height. Use a watch or timer to estimate wave frequency and period. It may help to use a marker to mark the side of the tank and watch the waves as they pass this mark. Record the following measurements in the Data section of your Making Waves Scientific Investigation Report.
   • Wave Height (cm)
   • Wave Length (in cm)
   • Period (in sec)
   • Frequency
3. In the Data section of your Making Waves Scientific Investigation Report, draw and label an accurate wave diagram of your observations. Label each part of the wave diagram using the data you just collected as labels. Also, label the crest and trough of the wave.

Observing Spilling, Surging, and Plunging

1. Attempt to make a spilling breaker by changing the shape of your beach. Record what happens in the data section of your Making Waves Scientific Investigation Report.
2. Attempt to make a plunging breaker by changing the shape of your beach. Record what happens in the data section of your Making Waves Scientific Investigation Report.
3. Attempt to make a surging breaker by changing the shape of your beach. Record what happens in the data section of your Making Waves Scientific Investigation Report.

Observing Refraction, Reflection, Diffraction

1. Set-up your beach so that the waves refract as they are breaking. In the Data section of your Making Waves Scientific Investigation Report, draw and label draw an accurate top-down illustration of the beach and water to show how you created this refraction.
2. Set-up your beach so that the waves reflect. In the Data section of your Making Waves Scientific Investigation Report, draw and label an accurate top-down illustration of the beach and water to show how you created this reflection.
3. Set-up your wave tank for that the waves diffract around an object. Use your stone, lump of clay, or similar heavy object. In the Data section of your Making Waves Scientific Investigation Report, draw and label an accurate top-down illustration of the beach and water to show how you created this diffraction.

Data

Use the spaces provided in the Data section of your Making Waves Scientific Investigation Report to record your data from this scientific investigation.

Data Analysis

In the Data Analysis section of your Making Waves Scientific Investigation Report, provide responses to the following questions. Make sure to completely answer each question.

1. Were you successful in your attempt to make a spilling breaker? Explain.
2. Were you successful in your attempt to make a plunging breaker? Explain.
3. Were you successful in your attempt to make a surging breaker? Explain.

Conclusion

Using the Conclusion section of your Making Waves Scientific Investigation Report, compose three to four sentences describing an overall conclusion based on your data. Were your hypotheses true or false, and how do you know? Use the data and notes that you collected from your investigation to form your conclusion. Make sure that you include information that you gained from data analysis to support your conclusion.

Experimental Sources of Error

On your Making Waves Scientific Investigation Report, provide responses to the following questions: Are there any sources of error? If so, what are they, and what could be done to minimize error?

 

Once you have completed the Making Waves Scientific Investigation Report, please submit your work to the dropbox.