2. What are waves and how are they related to matter? Waves are regular disturbances that carry energy through matter or space without carrying matter Ex: when you listen to music the speakers vibrate and create sound waves that reach your ears Ex: When you kick a soccer ball to a friend you are transferring energy (feel the force of the ball) as well as matter (ball)
3. Main Types of Waves Mechanical Electromagnetic Transverse Compressional Compressional Waves
4. Mechanical Waves Waves that require matter to carry energy are called mechanical waves Ex: sound travels through air (matter) from gas molecule to gas molecule to your ears Without air, you would not hear sounds When we drop water into the plate, this energyis transferred from molecule to molecule of water and creates waves
5. Electromagnetic Waves Waves that do not require matter to carry energy are called electromagnetic waves Ex: radio, TV, microwave, x-rays, Sun Ex: Can travel through the walls of your home and places like space
6. Transverse Waves Mechanical transverse waves, matter moves back and forth All electromagnetic waves are transverse Diagram: The high part of a transverse wave is called the crest. The low part of a transverse wave is the trough. The amplitude of the wave is the distance the crest rises above or the trough falls belowthe wave’s center line. Amplitude
7. Compressional Waves Mechanical waves can be transverse or compressional Compressional waves move matter forward and backward in the same direction the wave travels Ex: spring toy Only carries energy forward, the spring does not move along with the wave Ex: Sound waves are compressional waves
8. Sound Waves How do we make sound waves? Ex: drum When a drum is not being played the air particles are spread the same distance apart When the drum is hit, the surface moves down and the air particles move away from each other When the drum’s surface moves back up, the air particles are squeezed together The air particles transfer the sound energy through the air and to your ear
