Science AHSGE Standard VII Objective 2- Waves and Energy

Transverse Waves Transfer of energy through space or matter Transverse- Up and down movement perpendicular to direction Ex: Light and water waves Ex: Electromagnetic Spectrum

Compressional Waves Compression (Longitudinal)- Circular movement parallel to direction Ex: sound waves

Wave Characteristics: 1. Crest- Height of a wave 2. Trough- Bottom of a wave 3. Wave length- Distance from one crest or trough to another 4. Amplitude- Height of a wave from crest or trough to the medium 5. Frequency- Number of wavelengths passing a point in one second (Hertz); Shorter w.l. = higher frequency; Longer w.l. = higher freq. **The higher the frequency, the more energy, the most damaging

Wave Frequency The higher the frequency, the shorter the wavelength The higher the frequency, the stronger/more damaging the wave

Wave Characteristics

Reflection vs. Refraction Reflection- the bouncing off of a wave from an object Ex: Echos; sonographs; echolocation Ex: Reflected light helps you see Refraction- the bending of a wave as it passes through a substance Ex: Straw looks bent in a glass of water Ex: Prisms refract light to display rainbow

Reflection vs. Refraction

Sound Waves Sound waves- compressional waves that can not travel through a vacuum (empty space); must have matter for vibration Intensity- Volume of sound; determined by amplitude Pitch- Highness or lowness of sound; determined by frequency Sonic boom- Loud sound when object travels faster then the speed of sound; breaks the sound barrier Sound waves move fastest through solids Doppler Effect- Sounds increase as it moves towards you decreases as it moves away from you

Electromagnetic Spectrum Transverse waves which can travel at the speed of light in a vacuum Particles called photons

Light Waves Light waves- transverse Intensity- Brightness of light What you see is the result of light reflection ROY G. BIV (Lowest to highest frequency) Colors you see are reflected, while those you don’t are absorbed Red- Lowest energy/frequency and longest wavelength Violet- Highest energy/frequency and shortest wavelength

Light Uses Solar Power- Using sunlight to heat water and generate electricity Photoelectric Effect- Using light to trigger an electrical device Ex: Calculators, photographic lights, automatic doors at stores Polarized light- filtered light that minimizes glare; gets all light on same plane Ex: Sunglasses and tinted windows

Seismic Waves Earthquakes- Seismic Waves 1. Primary waves- fastest Travel through solids, liquids and gases 2. Shear/Secondary waves- second fastest Travel through solids only 3. Long waves- Slowest waves Travel only on surfaces

Seismic Waves