The Behavior of Waves

1. The Behavior of Waves

2. Reflection • Reflection occurs when a wave strikes an object and bounces off of it. • All types of wave can be reflected. • Sound reflection is an echo. • Light reflection in a mirror.

3. The Law of Reflection • Normal – line drawn perpendicular to the surface • The beam striking the mirror is called the incident beam. • The beam that bounces off the mirror is called the reflected beam. • Angles are measured between the beams and the normal.

4. The Law of Reflection • The angle of incidence is always equal to the angle of reflection.

5. Refraction • The wave speed is determined by the medium. • Different mediums, different speeds. • Because of the difference in speeds the wave will bend as it goes from one medium into another.

6. Refraction • Refraction is the bending of a wave caused by a change in its speed as it moves from one medium to another.

7. Diffraction • Diffraction the bending of waves around the edge of a barrier. • Diffraction and refraction both cause waves to bend. • Refraction occurs when waves pass from one medium to another. • Diffraction occurs when waves pass around an object in the same medium.

8. Diffraction & Wavelength • The amount of bending depends upon the wavelength and the opening being similar in size. • Light won’t diffract through a doorway, but sound will

9. Diffraction of Radio Waves • AM radio waves have longer wavelengths than FM radio waves. • Therefore, AM radio waves diffract around obstacles like buildings and mountains and FM won’t diffract as much • AM radio reception is often better than FM reception around tall buildings and natural barriers such as hills.

10. Interference • When two or more waves traveling through the same space at the same time. • They combine to form a new wave, the process is called interference.

11. Constructive Interference • When the two or more waves add together to form a larger amplitude than either of the other waves alone. • Energies add to transfer more total energy.

12. Destructive Interference • When the two or more waves add together to form a smaller amplitude than either of the other waves alone. • Energies subtract to transfer less total energy.

13. Standing Waves • A standing wave is when two waves equal in wavelength and amplitude, but traveling in opposite directions interfere with each other.

14. Resonance • The process by which an object is made to vibrate at its natural frequencies is call resonance.