TEKS 5G: Explore the characteristics and behaviors of energy transferred by waves, including acoustic, seismic, light, and waves on water as they superpose on one another, bend around corners, reflect off surfaces, are absorbed by materials, and change direction when entering new materials. What is a wave? A wave is a disturbance through a medium involving the transfer of energy from place to place. Energy is the ability to do work. Examples of waves include water waves, sound, and light. A medium is the material through which a wave travels. Most types of waves need a medium to travel through. Waves that require a medium to travel through are called mechanical waves. Examples of mediums include gases, liquids, and solids. Energy is needed to make a wave. Mechanical waves form when a source of energy causes a medium to vibrate. (contd.)

TEKS 5G: Explore the characteristics and behaviors of energy transferred by waves, including acoustic, seismic, light, and waves on water as they superpose on one another, bend around corners, reflect off surfaces, are absorbed by materials, and change direction when entering new materials. Mechanical waves There are three types of mechanical waves (classified by how they move through mediums) Transverse waves Longitudinal waves Surface waves Transverse waves A transverse wave vibrates a medium at right angles to the direction in which the wave travels. Waves that you make by shaking a rope are transverse waves. An electromagnetic wave is a transverse wave that involves the transfer of electrical and magnetic energy. Electromagnetic waves are not mechanical waves. They can travel through a vacuum, such as empty space, or a medium. (contd.)

TEKS 5G: Explore the characteristics and behaviors of energy transferred by waves, including acoustic, seismic, light, and waves on water as they superpose on one another, bend around corners, reflect off surfaces, are absorbed by materials, and change direction when entering new materials. Longitudinal waves A longitudinal wave vibrates a medium in the same direction in which wave travels. Examples of longitudinal waves include sound (acoustic) waves and the waves in spring toys. In a spring toy, the spacing between the coils varies as the wave vibrates the medium. An area where the coils are close together is called a compression. An area where the coils are spread out is called a rarefaction. (contd.)

TEKS 5G: Explore the characteristics and behaviors of energy transferred by waves, including acoustic, seismic, light, and waves on water as they superpose on one another, bend around corners, reflect off surfaces, are absorbed by materials, and change direction when entering new materials. Surface waves Surface waves are a combination of transverse and longitudinal waves. Surface waves travel along the boundary between two mediums. Ocean water waves are an example of surface waves. They travel along the boundary between water and air. Ocean water waves combine the up-and-down motion of transverse waves with the back-and-forth motion of longitudinal waves. The net result of this combination is to make each particle of water move in a circle.