level: waves
Questions and Answers List
waves
level questions: waves
| Question | Answer |
|---|---|
| whats a transverse wave | a wave that oscillates perpendicular to its propagation |
| whats a longitudinal wave | the vibrations are parallel to the direction of wave travel |
| black materials... | better emitters and absorbers / emit faster |
| Doppler effect | where there is a change in frequency and wavelength |
| em spectrum (longest wavelength first) | radio, microwave, infrared, visible, uv, X-ray, guns |
| what is refraction | the change in direction of a wave at such a boundary. bend. |
| whats reflection | hen a wave hits boundary between two media where the wave speeds differ, but the wave stays in the original medium instead of passing into the second medium. |
| what is diffraction | he spreading out of waves when they go through a gap, or past the edge of a barrier. |
| whats the refractive index | a measure of the change in the speed of light as it passes from a vacuum (or air as an approximation) into the material. |
| how does sound travel thru air | the air particles vibrate and collide with each other, causing the vibrations to pass between air particles. |
| critical angle | The angle of incidence when the angle of refraction is 90 o, and the ray changes from just refracting to total internal reflection, |
| whats the frequency of human hearing | 20 - 20,000 Hz |
| What is total internal reflection (TIR)? | When light travels through a medium and hits the solid-air boundary at an incident angle greater than the critical angle and is therefore reflected back into the solid as opposed to refracting out the other side |
| What uses are there for total internal reflection? | Endoscopes, optical fibres, etc. |