While traveling in the engine of a train, you are given the opportunity to activate the horn.  How is the sound you hear different someone near the tracks ahead of your train? How is the sound you hear different from someone in a car traveling next to the tracks at the same velocity?

This week, you will study the relationship between sound and the material in which the sound wave is disseminated. The speed of sound in one material may be greater than in another material due to changes in material properties. For example, a material's rigidity and/ or density can play a role. 

Sound waves and mechanical oscillations are common in many types of phenomena that you encounter daily. Musicians have an understanding of the characteristics of the sounds produced by their instruments, and this could create new ways for them to be creative with their art. Sonograms are used in technology, and ultrasounds are vitally important in medicine. Seismographs and sonar are sound wave-based technology that allows scientists and engineers to study the characteristics of the earth and under the sea. Technology-based on sound waves is used to enhance and improve our lives in many ways that are not obvious. In this unit and discussion, you will explore the science behind sound waves and their applications

Before you begin, be sure to review the following resource: