Sound And Light Flashcards
Plane mirror
A flat mirror that allows you to see reflections and reflects light in a way called specular reflection.
Refraction
The light rays when bend because they slow down or speed up. This happens when it enters a new medium.
Specular reflection
The perfect reflection of light- the angle of incidence is equal to the angle of reflection. If you can see your reflection in an object, it allows specular reflection.
Speed of sound
The speed of sound varies with each medium, but is 330 m/s through air.
Audible range
The human audible range is 20Hz to 20KHz. When we get older, we can not hear the higher pitched noises.
Diffuse scattering
This is when light travels into a rough surface. It bounces everywhere and the angle of incidence and reflection usually have no links. You can’t see you reflection in objects that cause this.
Incident ray
The light ray that travels directly into an object.
Law of reflection
With specular reflection, the angle of incidence is equal to the angle of reflection.
Vacuum
Where there is no matter. Longitudinal waves can’t pass through vacuums.
Pitch
This is how high or low a sound is. A higher frequency means a higher pitch.
Amplitude
How the distance between the equilibrium and the top of the wave. In sound, a higher amplitude is louder.
Frequency
How quickly a wave is emitted. A high frequency would mean a high pitched sound.
Ultrasound
An inaudible sound to humans. It is above 20KHz
Echo
When sound passes by someone and bounces back to them. This makes the person hear that noice many times.
Speed of light
Just under 1000 times faster than sound at 3000000 m/s.
Transverse waves
Oscillations that are at a 90 degree angle to the direction of energy transfer. They travel in straight lines and can travel through vacuums. They transfer energy, not matter.
Oscillation
An oscillation is a wave. One oscillation in a transverse wave is one wavelength.
Peak/Crest and trough
The peak/crest is the top of a transverse wave while the trough is the bottom
Medium
A medium is any type of matter that can allow a wave to travel.
Wave length
The distance between a point on a wave and the same point on the next.
Convex lens
A lens that goes out. In fixes long sighted people as it converges the light rays.
Concave lens
A lens that comes inwards. It fixes short sighted people as it diverges the light rays.
Reverberation
When a sound bounces of an object. This causes an echo.
Longitudinal wave
A wave where the direction of energy transfer is parallel to the direction of travel. They require a medium to travel through and transfer energy, not matter.
Reflected ray
The ray of light that bounces off an object.
Refraction
Refraction happens when light bends. Light bends because it enters a new medium. It speeds up or slows down. This causes us to see things closer or further away than they really are.
Angle of refraction.
The difference between the angle that light enters or exits a medium and the normal.
Retina
The object in an eye that catches light and converts it into an electrical charge to be sent to the brain.
Spectrum
The arrangement of colours together. A rainbow is a spectrum.
Dispersion
Dispersion is the splitting of light into the spectrum.
Wave
Something that travels in straight lines and transfers energy, not matter.
Cornea
The tough protective layer outside the eye. It is convex.
Lens
The lens is the object that focuses light onto the retina.
