Waves Flashcards
(38 cards)
What is the particle theory?
All matter is composed of particles
These particles are always in motion
Particles either create solids liquids or gasses
What are the structure of solids, liquids and gasses?
Solids have particles that are packed closely together to form a fixed shape and a strong attraction between particles. They have the least eneergy.
Liquids have particles that are close together but don’t form a fixed shape and a medium attraction between particles.
Gasses have particles that are far apart and don’t form a fixed shape and a weak force of attraction. They have the most energy.
What is conduction?
The transfer of heat through direct contact
What is convection?
The transfer of heat through a fluid (liquid or gas) caused by heat rising and cold air sinking in a cycle
What is radiation?
Energy that is transmitted in the form of rays, waves or particles
What are waves?
A disturbance in a medium that carries energy
What are transverse waves?
Waves that move perpendicular to the direction of the medium
What are longitudinal waves?
The medium to move parallel to the direction of the wave
Define and outline the common features of a wave
Wavelength - the distance between the peak of one wave to the next
Amplitude - the distance from the undisturbed position to the wavelength peak
Period - The time it takes for one wave to occur
Frequency - The number of complete waves passing a fixed point over a period of time/measured in hertz
Crest/Trough - The highest/lowest point in a transversal wave
Compression/Rarefaction - when the particles are tightly packed/spread apart in longitudinal waves
Explain sound waves
Longitudinal waves that move energy through a medium through compressions and rarefactions.
They are caused by vibrations and make sounds,
They travel fastest through solids because the particles are packed more tightly together and slowest through gasses.
Describe the relationship between frequency and pitch
They are directly proportional, the higher the frequency the higher the pitch due to the wavelengths and vice versa.
Pitch is described as high, medium or low (qualitative)
Frequency can be measured in hertz (quantitative)
Describe the relationship between amplitude and volume
They are directly proportional, the greater the amplitude the greater the volume and vice versa
Outline the electromagnetic spectrum
A line of different waves placed along the spectrum from longest wavelength/frequency to shortest
Wavelength and frequency are directly proportional
It consists of radiations that travel in transverse waves.
Describe light
The movement of energy through a vacuum by electromagnetic transverse waves (all electromagnetic waves travel the same speed through a vacuum)
It can be seen by the human eye
It travels in a straight line and can be reflected, refracted or absorbed.
What is the law of reflection?
When the incidence ray, the normal and the reflected ray lie on the same line, the angle of incidence is equal to the angle of reflection.
Label reflection diagram
- Incidence ray
- Reflected ray
- Angle of incidence
- Angle of refelction
- Normal
- Mirror
- Point of incidence
How do plane mirrors use reflection?
They produce a laterally inverted, virtual image that is the same size and distance from the mirror as the object
e.g. automobiles, microscopes and telescopes
Draw a digram of a plane mirror
How do concave mirrors use reflection?
They reflect the incident rays to where they converge called the focus.
e.g. make-up mirrors, dental mirrors and flashlights
Draw a digram of a concave mirror
How do convex mirrors use reflection?
The reflection of parallel incident rays diverge
Draw a digram of a convex mirror
Define refraction
The bending of light rays in response to the density of a medium.
e.g. when sun light moves from air to water and when a light source travels through a glass box
Draw a digram of refraction
