The Nature of Waves

1. The Nature of Waves Pgs. 4 - 9

2. Waves are Everywhere • A wave is any disturbance that transmits energy through matter or space. • There are waves in the ocean, microwaves, light waves from the sun, radio waves, and sound waves. • Where are waves in your everyday life?

3. Waves Carry Energy • Energy can be carried away from its source by a wave, but the material through which the wave travels does not move with the energy. • For example, when you talk on the phone, you do not get a rush of air in your ear every time you hear someone talk.

4. Waves use energy to do work on everything in its path. • Objects floating in the ocean are moved up and down by waves as they pass.

5. Energy Transfer Through a Medium • A medium is a substance through which a wave can travel, such as a solid, liquid or gas. • When particles vibrate, they pass energy to the particles next to them. • The energy of the wave is transmitted through the particles of the medium.

6. Waves that require a medium are: sound waves, ocean waves, seismic waves, and waves on a guitar or cello strings. • Waves that require a medium are called mechanical waves.

7. Energy Transfer Without a Medium • Waves that do not require a medium are: visible light, microwaves, TV and radio waves, x-rays, gamma rays, infrared waves. • These waves are all called electromagnetic waves. • They can travel through substances, but are not required to travel through them.

9. Types of Waves • Waves are also grouped on how they move in a medium. • Transverse waves move perpendicular to the direction the wave travels. • Transverse waves have crests, high points, and troughs, low points. • All electromagnetic waves are considered transverse waves.

11. Longitudinal waves • Longitudinal waves vibrate back and forth along the path the wave travels. • These waves have compressions, areas where particles are crowded, and rarefractions, areas where particles are spread out. • They are similar to crests and troughs.

12. Combinations of Waves • Waves can combine when they occur at the boundary between two media. • A longitudinal and transverse wave combine to form a surface wave. • Surface waves look like transverse waves but move in circles, rather than up and down.