Waves and Radiation Flashcards
What do waves carry?
Energy
What are the two main types of waves?
Longitudinal and transverse waves
What is another name for longitudinal waves?
Compression waves
How do the particles in longitudinal (compression) waves move?
Backward and forward in the same as the wave, e.g. sound (refer to diagram)
How do the particles in transverse waves move?
At right angles to the direction of the wave, e.g. electromagnetic radiation such as light and water waves. (refer to diagram)
What type of waves are water waves?
Transverse waves
What type of objects create sound?
Vibrating objects.
Quicker vibrations produce…?
Higher pitch sounds
Bigger vibrations produce…?
Louder sounds
What does sound need present in order to be transmitted?
Molecules
Do sounds travel quicker through solids or gases?
Solids
What is reflected sound called?
Echo
What type of sound is music?
Sound that has a regular pattern, sounds are pleasant and peaceful
What type of sounds is noise?
Sound that has no pattern, it is not pleasant to listen to
What is a ultrasound?
High pitch sound waves used to study internal body structures.
What is the speed of sounds in air?
340m/ sec or 1220km/ hr
How does electromagnetic radiation travel?
By transverse waves.
Order these from short wavelength/ high frequency to long wavelength/ low frequency:
U.V, Infra- red, microwaves, light, radiowaves, X- rays, gamma rays
Gamma rays X- rays U.V Light Infra- red Microwaves Radiowaves
What are mirrors?
Reflected light
Flat mirror
Refer to diagram
Concave mirror
Refer to diagram
What do lenses do to light that passes through them?
They refract light.
What do concave lens do to light rays?
Bend them apart (refer to diagram)
What do convex lens do to light rays?
Refracts light rays to a point. The more curved the lens, the greater the refraction. (refer to diagram)
Name some objects that contain convex lens.
Optical instruments such as cameras, telescope, overhead projector and microscopes.
White light consists of the colours of the spectrum….. together
blended
What are the primary colours?
Red, green and blue
A red object reflects … light and …. other colours
red, absorbs
What colours do white reflect and absorb?
Reflects all colours and abosrbs none
What colours do black reflect and absorb?
Reflects none, absorbs all colours
What cells in the retina of the eye detects colours?
Cone (nerve) cells
What is refraction?
Bending of light
Why does light refract?
It travels at different speeds in different density materials.
What are X- rays used for?
To detect broken bones
What is frequency?
The number of waves that passes a given point per second.
