The sound waves of a moving siren are closer together in front of the police car than they are behind the police car. This change is called the Doppler Effect after the man who first described it in 1842.įigure 1. As the vehicle passes, it travels a small distance away between sending each sound wave so the sound waves are more stretched out, and make a lower sound (see Figure 1). So for you, the sound waves are squashed closer together and make a high sound. Have you noticed how the noise of a speeding vehicle, like a motorcycle, car, train or plane, seems to be constant as it approaches you then as it goes past, the noise drops or falls in pitch, to a lower note? As the vehicle moves toward you, it travels a small distance closer between sending out each sound wave. You have just learned two of the three important characteristics of sound energy that we will discus today - sound volume and pitch. What is this sound like? Is it a higher sound? We call this characteristic of sound, pitch. How would you describe that sound? Can you tap on your desk louder? Now, really softly? What do we call this change in sound? We call this characteristic of sound, volume. What did you hear? (Have a few students describe the different sounds they heard.) These are all sounds and we will be learning about sound energy today. Have the students close their eyes and sit quietly for 30 seconds. International Technology and Engineering Educators Association - Technology In such collisions, some energy is typically also transferred to the surrounding air as a result, the air gets heated and sound is produced.Įnergy can be transferred in various ways and between objects. When objects collide, energy can be transferred from one object to another, thereby changing their motion. Use evidence (e.g., measurements, observations, patterns) to construct an explanation.Īlignment agreement: Thanks for your feedback!Įnergy can be moved from place to place by moving objects or through sound, light, or electric currents.Īlignment agreement: Thanks for your feedback! Energy is present whenever there are moving objects, sound, light, or heat. This lesson focuses on the following Three Dimensional Learning aspects of NGSS: Make observations to provide evidence that energy can be transferred from place to place by sound, light, heat, and electric currents.Ĭlick to view other curriculum aligned to this Performance Expectation Explain sound as a form of communication.Describe sound energy as traveling in waves.Define volume, pitch and frequency as they relate to sound energy.Give several examples of engineering products that involve sound.Ultrasound can detect tiny flaws in materials used to make parts-from bridge bolts to aircraft wings.Īfter this lesson, students should be able to: Engineers also design instruments that "listen" to ultrasound and infrasonic sound waves. Sonar is also used to search for undersea objects such as wrecks, submarines, rocks, icebergs, whales and fish. Ships use sonar to navigate and map the seabed by measuring water depth. Sonar devices send ultrasound waves into an ocean and create images based on which waves are bounced back to the device. Sound waves traveling through the air are collected by radio antennas. This engineering curriculum aligns to Next Generation Science Standards ( NGSS).Įngineers use their knowledge of sound waves to create radio and sonar devices. They also identify the different pitches and frequencies, and create high- and low-pitch sound waves. They explore how sound waves move through liquids, solids and gases. They learn to describe sound in terms of its pitch, volume and frequency. Through hands-on activities and demonstrations, students examine how we know sound exists by listening to and seeing sound waves. Students are introduced to sound energy concepts and how engineers use sound energy.
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