Heat/Sound/Light Test 2023 Flashcards
What is energy transfer?
The process by which energy is relocated from one system to another.
What is conduction?
Conduction is the process where heat is transferred from a hotter object to a colder object
What things conduct heat and electricity the best?
Metallic solids (as particles are closer together), metals (steel, copper).
What is convection?
Movement in a liquid due to the heating and cooling process. Creates convection currents
What are convection currents?
Convection currents are heat-driven cycles in the fluids. As water closer to a heat source gets hotter, it rises to the top. Cooler water sinks back down. This rising and sinking cycle creates movement e.g. boiling.
What are insulators?
Things that hold in heat well - they do not transfer heat easily.
List 5 conductors
Copper, steel, iron, bronze, silver,
List 5 insulators
Glass, wool, wood, fibreglass, ceramics, styrofoam, plastic, rubber
What is the direction of heat transfer?
Heat transfers only in the direction of objects that are colder. The difference in temperature determines the direction.
What is a wavelength?
Distance between wave’s crests
What type of wave does sound travel in?
Longitudinal
What is frequency?
Frequency, or pitch, is the number of times a sound wave repeats itself. Many waves produce a higher pitch whilst fewer waves produce a lower pitch. Shorter the wavelength, higher the pitch.
What is amplitude?
The strength of a sound/volume or loudness. It is measured in decibels (dB). Demonstrated by height of the crest
What are compressions?
A region in a longitudinal wave where particles are the most compressed (usually top of wave)
What are rarefactions?
Particles in the wave become more spread out at the trough of the wave - a decrease in the density of the matter (eg. air) around the wave as it travels through
What is the top of a wave called?
The crest
How do waves travel?
They oscillate - move back and forth, but do not displace matter in the area
Can sound travel through a vacuum, or does it need surrounding matter?
Sound needs matter - eg. air
What state of matter do sounds travel the fastest through?
Solids - particles packed close
What is the lowest part of the wave called?
The trough
What is a wavegraph?
Graph used to show and record sound waves and the compression and rarefaction of particles.
What is the visible spectrum?
The segment of the electromagnetic spectrum that the human eye can view
What type of wave does light travel in?
Transverse
What wavelengths can the human eye detect?
300-700
Does light need particles to move?
No - it can travel through a vacuum.
What is a transparent object?
Clear - like glass - all light can travel through
What is a translucent object?
Slightly clear - like frosted glass - some of the light can pass through
What is an opaque object?
No light can pass through as it is not able to be seen through - solid.
How can we see colours?
Light reflects/bounces off an object and into our eyes
What are the primary colours of light?
Red, green, blue
What is refraction?
Where light is “bent” as it moves through different media (liquids, solids etc) as they have different amounts of particles which the light bounces off
How are colours seen?
Objects are seen as certain colours as they reflect a colour but absorb all others.
Where do all colours originate from?
White light
How is black created?
It absorbs all colours
What makes white?
All colours reflect
What is infrared light?
A bit below the visible spectrum - heat
