Characteristics of Waves
Bill Nye Waves http://www.youtube.com/watch?v=OA82SgDn1Qc
What are Waves? Rhythmic disturbances that repeat the same cycle of motion and transfer energy Two Types: Electromagnetic and Mechanical
Laptops- Waves Use the computers to conduct research on waves. www.physicsclassroom.com is a great site. Create a cheat sheet flyer. On one side include the types of waves and their major parts: Electromagnetic Wave, Electromagnetic Spectrum, Mechanical Wave, Transverse Wave, Compressional/Longitudinal Wave On the other side, include the parts of a wave. Include: Amplitude, frequency, wave height, wave length, crest, trough, wave energy, wave speed
Parts of a Wave The crest is the highest point on a wave.
Trough Valley between two waves, is the lowest point.
Wavelength (λ) The horizontal distance, either between the crests or troughs of two consecutive waves.
Wave Height A vertical distance between a wave's crest and the next trough.
Amplitude - The peak (greatest) value (either positive or negative) of a wave. The distance from the equalibrium (rest point) to the trough or crest.
Energy In mechanical waves energy is directly proportional to the square of the amplitude. In electromagnetic waves, energy is carried in photons (little packets of energy) Energy in electromagnetic wave is proportional to the waves frequency.
Frequency (f ) Is the number of complete waves or cycles of oscillation in a given period of time Measured is hertz Period- is the time it takes to complete one full cycle. Measured in seconds
Wave Speed A measure of how fast a wave is moving. For mechanical waves it depends on the state of matter
National Geographic Wave Simulator
Electromagnetic Waves Read the article and highlight important information.
Electromagnetic Waves From the article: write down 3 important facts. At least one thing you didn’t know. At least one question about the information. Which part of the electromagnetic spectrum is the strongest? Which part of the electromagnetic spectrum is the weakest?
Electromagnetic Waves Waves that do not need a medium (matter) to travel in. Can travel in a vacuum (like outer space) as well as air, water and glass, but can be absorbed by opaque materials Light, X-rays, Radio Waves
Electromagnetic Spectrum
Mechanical Waves Waves that use matter to transfer energy: Travel through air, as well as solids, liquids and other gases. No matter, no wave…..like in outer space.
Transverse Waves Type of mechanical wave Wave energy causes the matter in the medium to move up and down or back and forth at right angles to the direction the wave travels.
Longitudinal or Compressional Wave Type of Mechanical Wave Matter in the medium moves forward and backward along the same direction that the wave travels. Slinky
Compare and Contrast Compare and contrast electromagnetic waves with mechanical waves.
Five Important Properties of Waves
Reflection Refraction Diffraction Interference Absorption
1. Reflection: When a wave hits a reflecting surface, it is reflected outwards at the same angle as it came in.
1. Reflection Mirror Incident light beam Reflected light beam
1. Reflection
2. Refraction: Waves bend when they go from one medium to another (like from air into water or glass)
2. Refraction
2. Refraction:
2. Refraction Different wavelengths bend at different angles, which is what makes a prism able to separate white light into all its colors Refracted Colors Air White Light Glass Prism
2. Refraction
2. Refraction Refraction is also what makes lenses work. Light bends when it goes from air to glass. Air Incoming light Focused light Lens
3. Diffraction Light bends when it goes around around obstacles and through openings
When two waves run into one another, they add if crests overlap, and subtract if troughs overlap 4. Interference
When waves are absorbed by material, depending on the material depends on the amount of absorption.
Properties Flyer Using the knowledge you just gained plus the notes/textbook, create a colorful flyer that represents the properties that we talked about.