Light and Waves Flashcards
What are longitudinal waves?
A wave that moves in the same direction as the direction in which the particles are vibrating.
What are transverse waves?
A wave that moves in a direction at right angles to the way in which the particles are vibrating.
Describe how light travels through translucent and opaque materials.
Translucent: light travels through it but the rays are scattered.
Opaque: light can’t travel through opaque materials, some is reflected and some is absorbed.
What’s specular reflection?
Reflection from a smooth, flat surface is named specular reflection and it happens with a flat mirror.
What’s diffuse reflection?
This happens when a surface is rough and the light is scattered in all directions.
How do we see?
We can only see objects that reflect light. As light strikes a surface, it is reflected back, and enters our eye and we perceive the colours that are reflected.
What’s a pinhole camera?
A very simple camera consisting of a light-proof box, some sort of film and a pinhole.
What is the law of reflection?
Sound waves and light waves reflect from surfaces. The angle of incidence equals the angle of reflection. This is called the law of reflection.
What’s refraction?
Refraction is the bending of light as it travels from one substance to another.
How do lenses work?
The incoming light rays go through the lens and light rays are reflected by the lens.
What are the 4 parts of a camera?
Lens which focuses the light, sensor which captures light and converts it into signals which result in an image, aperture which allows light into the camera and a shutter which opens when a picture is taken.
What is the structure of the eye? (7)
Rod cells and cone cells in the retina change light to nerve impulses, the optic nerve sends a message to the brain, pupil, coloured iris controls size of pupil, lens and cornea.
What are filters?
All filters let some “stuff” through while stopping other stuff and filter paper lets through liquid but stops solids. The red filter would only allow red light through.
The blue filter could only allow blue light through.
What are rod cells sensitive to?
Rods are most sensitive to light and dark changes, shape and movement.
What are cone cells sensitive to?
Cones are most sensitive to one of three different colours (green, red or blue) view colours.
