1. Waves, Sound, & Light Energy

2. Wave: a disturbance that transfers energy from place to place

3. Wave Properties: High point is the crest, Low point is the trough
From rest position to crest is amplitude
From crest to crest is wavelength
The number of complete waves that pass a given point in a certain amount of time is frequency .

4. Frequency is measured in hertz (Hz)
A wave that occurs every second has a frequency of 1 Hz.
Speed of the wave = wavelength x frequency.
Ex: 2 cm x 2 Hz = 4cm/s
Frequency = speed ÷ wavelength
Ex: 4 cm/s ÷ 2 cm = 2 Hz
Wavelength = speed ÷ frequency
Ex: 4 cm/s ÷ 2 Hz = 2 cm

5. Interference: the combination of waves at the same place at the same time (constructive v. destructive)

6. Sound: vibrations transmitted through a medium detectable by auditory sense organs

7. Echo: bouncing back of waves upon reaching a surface.

8. Speed of sound depends on the elasticity, density & temperature of the medium
increased elasticity = increased speed (snaps back to shape quickly)
increased density = decreased speed (molecules don’t move freely)
increased temperature = increased speed (molecules move more freely)
In general, sound travels fastest in solids, then liquids,
& slowest in gases

9. Doppler Effect: the apparent change in frequency of a wave as the source moves in relation to the observer
Pitch: how high or low the frequency of a sound is (determined by frequency)

10. Decibels (dB): relative intensity of sound (determined by amplitude).
Resonance: an effect in which
the vibration of one object
causes the vibration of another object at a natural frequency.

11. Electromagnetic waves are produced when something accelerates an electric charge and requires no medium to travel in and they travel in all directions.
Electromagnetic Spectrum: the range of electromagnetic waves placed in order from longest to shortest wavelength

12. Visible Light: the ROYGBIV segment of the electromagnetic spectrum
Combination of all colors of light makes white light.
Color of a substance is what color(s) it reflects, it absorbs all other colors

14. Transparent: a material that allows all light through
Transparent: a material that allows all light through. (Example: window glass)
Translucent: a material that lets some light through, but image lacks details.
(Example: shower door)
Opaque: a material that lets no light go through.
(Example: block wall)

15. Reflection: bouncing back of waves upon reaching another surface
Angle of Incidence = Angle of Reflection: The reflected angle is equal in degrees to the angle in which the light enters (angle of incidence). _V_

16. Diffraction: bending of a wave as it passes through matter with openings that separate it by wavelength.
Refraction: Bending of waves due to a change in speed when a light goes through different mediums.

17. Lenses & Mirrors
Plane – flat surface.

18. Lenses & Mirrors
Concave – curves inward Convex – curves outward

19. Origin of Light: Emission of excited electrons/radiation from atoms.
Photon: a discrete bundle (or quantum) of light energy.
Dual Nature of Light: light has properties of both a wave & a particle