          Wave physics is everywhere. Concepts like reflection, refraction, and superposition are intrinsic to the function of devices important to the scientist and consumer alike. These important ideas are often treated in a vacuum; students are rarely challenged to connect them to the real world. These activities encourage students to think about the applicability of waves by framing basic concepts in the context of ocean sensing. Activities include writing word problems, building a directional microphone, and geometric laser range finding.               Students know that waves transport energy. Students can describe the physics of the SOFAR channel using the concept of refraction. Students know how to solve problems involving sound speed, travel time, and distance. Students know a variety of scientific instruments that rely on underwater acoustics. Students can describe the concept of superposition in the context of interference. Students know what a spectrum analyzer is and what it does. Students know that parabolic reflectors focus energy and are used in a number of applications. Students know the difference between coherent and incoherent light. Students know what a LASER is and how it is different from other light sources. Students can use trigonometry to calculate distances with a simple LASER range finder. Waves carry matter. Sound waves travels through as a transverse wave. LASERs are small, colored flashlights. Once waves are added together, the original waves are totally lost. A medium with a higher sound speed allows sound to propagate more efficiently. This activity includes three PowerPoint based lectures, one in class problem writing activity (this can be done in a computer lab or with smart phones in the classroom), and two laboratory exercises. Each lab activity will take about two class periods for data collection and analysis. This activity is designed for use over two class periods. After an approximately 20-minute introductory presentation, students work in groups to write word problems based on one of the topics discussed. All problems will utilize the formula v = d/t. Students do research on the topic to get appropriate units and vocabulary. Each group then presents the problem for their classmates to solve. Included is a worksheet for students to fill out while they do research. It is meant to guide the group through crafting their problem. Examples of finished products are also included. This activity is for use over three class periods. The first period is dedicated to the introductory lecture. The lecture is broken up by several short activities: students play with the sound sources, download and use the required spectrum analyzers, and the groups then play with both devices together. There is no particular structure for these explorations. They are meant merely to familiarize the class with the tools they will use later. The second day, students collect data with the directional microphones. The final day is dedicated to analysis and discussion. The lab activity sheet includes data charts, analysis, and discussion questions. A teacher version is available. Materials (one per group): smart phone, headset with microphone, salad bowl (or other parabolic reflector), sound source, wire, meter stick. This lesson is to be used over one or two class periods. After a short introductory lecture, students will build a laser range finder. They will be required to come up with the appropriate trigonometric relationship to compute the relevant distances. After recording the angles, they can do the required analysis the following class period or as homework. The lab activity sheet includes data charts, analysis, and discussion questions. A teacher version is available. Material (one per group): laser pointer, microscope slide, meter stick, mirror, protractor, an object to use as a target. These lessons were given as part of the waves unit in an Advanced Physics class. The lessons were also given to Regular Physics classes with some minor tweaking. Class periods were 55 minutes long. Students should have some experience with algebra, geometry, and trigonometry. Students should be familiar with some basic wave concepts (i.e. parts of waves, difference between longitudinal and transverse waves, etc.). Waves in the Marine Environment is a great way to introduce many of the concepts explored in these lessons. Students can be graded on completion of data collection and analysis. Worksheets with instructions, data charts, and analysis questions are provided with each laboratory activity. For the word problem activity, students were assessed on the quality of the problems they wrote and how well they could solve those written by their peers.               a. Students know waves carry energy from one place to another. b. Students know how to identify transverse and longitudinal waves in mechanical media, such as springs and ropes, and on the earth (seismic waves). c. Students know how to solve problems involving wavelength, frequency, and wave speed. d. Students know sound is a longitudinal wave whose speed depends on the proper� ties of the medium in which it propagates. e. Students know how to identify the characteristic properties of waves: interference (beats), diffraction, refraction, Doppler effect, and polarization. a. Select and use appropriate tools and technology (such as computer-linked probes, spreadsheets, and graphing calculators) to perform tests, collect data, analyze relationships, and display data. b. Identify and communicate sources of unavoidable experimental error. c. Identify possible reasons for inconsistent results, such as sources of error or uncontrolled conditions. d. Formulate explanations by using logic and evidence. e. Solve scientific problems by using quadratic equations and simple trigonometric, exponential, and logarithmic functions. Solve scientific problems by using quadratic equations and simple trigonometric, exponential, and logarithmic functions.                LIDAR Aircraft (courtesy NOAA) Fourier Lite (courtesy Apple) Acoustic Thermometry of Ocean Climate (ATOC) Map (courtesy SIO) Lesson Specifics Grade Level: 9-12  SIO Entrance Scripps Pier Contact Us COSEE  |   SERC  |   SIO  |   OSU Design EarthRef.org Sponsored by NSF and NSDL     