Waves Flashcards
(20 cards)
What happens when light reflects off a plane mirror?
Light reflects at the same angle it hits the mirror, creating a virtual image that appears the same distance behind the mirror as the object is in front.
What is a virtual image?
An image that cannot be projected onto a screen and appears to be behind the mirror.
How fast does light travel?
Light travels at approximately 300,000,000 metres per second in a vacuum and travels in straight lines through uniform media.
What happens when light passes from one material to another?
Light is refracted (bends) at the boundary between two different materials.
How does a pinhole camera work?
Light travels in straight lines through the pinhole, creating an inverted image on the screen inside the camera.
How are the eye and camera similar?
The physics of light passing through a camera and the eye are essentially the same - both use lenses to focus light.
What happens when white light passes through a prism?
White light can be dispersed by a prism to give a range of colours (spectrum).
What does a colour filter do to white light?
A colour filter allows only certain colours to pass through and absorbs all other colours.
How do coloured objects appear in white light?
Coloured objects reflect their own colour and absorb all other colours from white light.
What are the primary colours of light?
Red, green and blue are the primary colours that can be projected and combined.
What colours are made when primary colours combine?
Primary colours can be combined to make magenta (red + blue), yellow (red + green), cyan (blue + green) and white (all three).
What are transverse waves?
Waves where the vibrations are at right angles to the direction the wave travels, like light waves.
What are longitudinal waves?
Waves where the vibrations are in the same direction as the wave travels, like sound waves.
What properties do all waves have?
All waves have amplitude, frequency and wavelength.
How are sounds produced?
Sounds are caused by vibrations of objects.
Do sound waves need a medium to travel?
Yes, sound waves require a medium (like air, water or solids) to travel through, unlike light which can travel through a vacuum.
Why does sound travel much slower than light?
Sound needs particles to vibrate and transfer energy, whilst light is electromagnetic radiation that can travel through empty space.
How do we hear sounds?
Sound waves cause the eardrum to vibrate, and these vibrations are detected by the ear.
What affects how loud a sound seems?
The loudness of a sound depends on the amplitude of the vibration causing it - larger amplitude means louder sound.
What affects the pitch of a sound?
The pitch of a sound depends on the frequency of the vibration causing it - higher frequency means higher pitch.
