1. Waves
Chapter 11

2. Wave Properties Newton’s Laws govern the motion of waves
All waves transmit energy
Water, sound, light

3. Wave types Mechanical waves Transverse wave
water, sound, waves that travel down a spring
Require a medium (water, air, ropes, springs)
Transverse wave
A type of mechanical wave
Wave vibrates perpendicular to the direction of the wave motion

4. Wave Types Longitudinal Surface Wave
Particles move parallel to the direction of the wave motion
Sound, fluids
Surface Wave
Particles both parallel and perpendicular to the direction of the motion
Characteristics of long. And transverse

5. Measuring a wave
Drawing
Frequency
Speed

6. Assignment
Page 387 (1-4)

7. Boundaries

8. Superposition of Waves
2 waves in the same place in the medium at the same time
Pulse down meeting a reflected pulse
Each affects the medium independently
2 or more waves can combine to form a new wave
Principle of superposition

9. Interference
If the two waves are in opposite directions, they can cancel or form a new wave of less or greater amplitude
The result of the superposition of 2 or more waves is interference
Wave interference can be either constructive or destructive

10. Destructive Interference
The superposition of waves with equal but opposite amplitudes causes destructive In.
When 2 pulses with = but opp. Amplitudes meet, the displacement of the medium at each point in the overlap region is reduced (↑ & ↓)
When the pulses meet (node) the displacement is zero. The waves pass through each other unchanged and resume their original form as they continue to move

11. Constructive Interference
Occurs when the wave displacements are in the same direction (↑ & ↑)
The resulting wave has an amplitude larger than any of the individual waves
The point where the 2 waves meet that has the largest displacement is the antinode

12. If the pulses have opposite and unequal amplitudes, the resultant pulse at the overlap is the algebraic sum of the two pulses
Page 394

13. Waves in >1 dimension
Mechanical waves move in 1D, Surface water waves move in 2D, Sound and electromagnetic waves move in 3D
A ripple tank can be used to show the properties of 2D waves
The wave pulse travels toward a barrier that reflects the wave (incident wave moves upward and the reflected wave moves to the right)

14. Diagram Ray diagrams model the movement of waves
Rays show the direction of the wave (drawn at right angles to the crests)
The direction of the barrier is shown with a line drawn at a right angle
Called the normal
θi = θr (law of reflection)

15. Diffraction
Drawing
Reflection, refraction, and diffraction will be used in optics