1. Ch Types of Waves
Wave

2. Section 11.1 Objectives Recognize that waves transfer energy.
Distinguish between mechanical waves and electromagnetic waves.
Explain the relationship between particle vibration and wave motion.
Distinguish between transverse waves and longitudinal waves.

3. What is a wave?
A wave is a disturbance that transmits energy through matter or space.
A wave is not made of matter.
Most waves travel through a medium.
Figure 11-1
A stone thrown into a pond creates waves.

4. Mechanical Waves Examples of Mediums:
Water
Air
Earth
Mechanical Waves are waves that require a medium.
Medium is the matter through which a wave travels.
Almost all waves are mechanical waves with the exception of electromagnetic waves (light).

5. Electromagnetic Waves
Electromagnetic waves are waves caused by a disturbance in electric and magnetic fields and that do not require a medium; also called a light wave.
Visible light is only one part of the electro-magnetic spectrum

6. Energy of a Wave
Energy may spread out in spheres that increase in size as a wave travels outward.
Waves transfer energy.
The bigger the wave, the more energy it carries.
We know waves carry energy because they can do work.
Ex: water waves carry a leaf or beat in water; sound waves can do work on your eardrum.

7. Vibrations and Waves Vibrations involve transformations of energy.
As the pendulum is pulled away from its resting position, it gains gravitational potential energy. As it swings the opposite direction, the potential energy is transformed to kinetic energy.

8. Wave Motion Vs. Particle Vibration
Waves are related to vibrations.
Most waves are caused by a vibrating object.
EM waves may be caused by vibrating charged particles.

9. Transverse and Longitudinal Waves
Transverse waves are waves that cause the particles of a medium to vibrate perpendicularly to the direction the wave travels.
Ex: Light Waves
Longitudinal waves are waves that cause the particles of the medium to vibrate parallel to the direction the wave travels.
Ex: Sound Waves

10. Surface Waves In a surface wave, particles move in circles.
Ocean waves are surface waves at the boundary between
the air and water.

11. Section 11.1 Summary
A wave is a disturbance that carries energy through a medium or through space.
Mechanical waves require a medium through which to travel. Light waves, also called electromagnetic waves, do not require a medium.
Particles in a medium may vibrate perpendicularly to or parallel to the direction a wave is traveling.