Energy Transfer and Communication Flashcards
AT2
What is the particle model of matter?
- Particles are constantly moving
- All matter is composed of particles
- When you cool down matter, the particle bonds will grow closer, forming a solid.
- When you heat up matter, the particles bonds weaken, forming a liquid or gas
What is conduction?
The transmission of heat via contact from matter to matter, particle to particle.
What is convection?
Convection occurs in the form of convection currents. In the example of water, warm water is less dense and rises. It is replaced with denser, cooler water.
What do waves carry?
Waves are carriers of ENERGY.
As waves travel through a medium, they lose energy.
Explain longitudinal waves in terms of compression and refraction.
Longitudinal waves move through compression and refraction. In refraction, they’re forced apart, and in compression, they’e forced together.
The energy in the wave disturbs the first particle in the medium, which will disturb the second and so on.
Draw a longitudal wave with labels.
||| | | | ||| | | |
*compression
*rarefraction
Explain transverse waves in terms of it’s properties.
FREQUENCY -
Number of waves passing a fixed point in a given amount of time. It’s measured in HERTZ and the symbol is (f)
PERIOD -
amount of time it takes for one wave to occur. Measured in SECONDS.
Wavelength -
Distance between the top of one wave and the next wave. It’s often measured in METRES
Amplitude -
Distance between undisturbed position of the wave and it’s peak. Measured in METRES
Crest -
Peak of wave
Trough -
Lowest part of wave
Wave Height -
Distance between crest and trough
Draw a transverse wave with labels.
~~~~~~~~~~
*Amplitude
*Wavelength
*Frequency
*One wave
*Crest
*Trough
*Wave height
Distinguish between transverse and longitudinal waves.
Transverse waves move perpendicular to the direction of the wave, whereas longitudinal move parallel
Explain how different mediums affect the transmission of sound.
Sound is a longitudinal wave, meaning it requires particles to be disturbed.
Based off this logic, sound travels fastest in solids, where particles are more dense.
This why a vacuum (empty space) is silent, and why it’s easier to hear through walls than across a field.
*When temp increases, the speed of sound increases
Describe the relationship between frequency and pitch
High frequency = higher pitch of sound
Describe the relationship between amplitude and volume.
larger amplitude = larger volume
Outline all the waves on the electromagnetic spectrum.
Radio waves
Micro waves
Infared waves
Visible Light
Ultra violet waves
X Rays
Gamma Rays
Radio -> Gamma is increased frequency.
Gamma -> Radio is increased wavelength
Describe movement of light through a vacuum.
Light travels through a vacuum, whereas sound CANNOT.
State the law of reflection.
The ANGLE OF INCIDENCE = ANGLE OF REFLECTION.
Find the angle of incidence using
90 degrees - given angle
Draw and label a diagram demonstrating the law of reflection.
N/A
Name all the labels in a law of reflection diagram.
*Incident ray
*angle of incidence
*normal
*angle of reflection
*reflected ray
*mirror
*point of incidence
How is an image formed in a plane mirror?
*The size of the image is the same as the physical object
*The image is erect (right side up)
*The image is laterally inverted
*The image appears “behind” the mirror
Define refraction.
The bending of light rays in response to the density of a medium.
Explain the use of refraction in optical instruments.
By adjusting the thickness of glasses, the focal point changes because there is more or less refraction. This means the light can be directed onto the retina properly.
More longsighted = more convex
Shortsighted = concave
Draw a diagram demonstrating refraction.
N/A
Name all the labels in a refraction diagram.
*Two different mediums
*Incident ray
*Refracted ray
*Angle of incidence
*Angle of refraction
Identify what white light is made up of.
All of the colours.
Explain the appearance of coloured objects.
An object appears a certain colour because it will absorb all colours of light rays except the colour it is. This ray is then reflected and we see it appear a certain way.
Give examples of uses of electromagnetic radiation.
Radio = radio stations
Micro = microwaves
Infared = reveals objects in space that can’t be seen with visible light
Visible light = only part of the EM spectrum the eye can see; sight
UV waves = cures ink and resin, kills bacteria, suntanning
X-Ray = detect breaks and fractures.
Gamma Rays = radiotherapy and used to sterilize medical instruments.
What direction does the medium move in a longitudinal wave?
It moves PARALLEL to the direction of the wave.
What direction does the medium move in a transverse wave?
Perpendicular to the direction of the wave.
How do images appear in convex mirrors?
*Image is virtual
*Image is erect
*Image formed is SMALLER than the real object
*Image is inverted
How do images appear in concave mirrors
*Image is REAL
*Image is magnified (the image is not real when it’s magnified)
*Image gets smaller the further you go from the mirror, which is what generates the real image
Draw diagrams demonstrating light reflecting off plane, convex and concave mirrors.
N/A
What is “focal length”
Distance between mirror and focal point.
Where is the focal point in convex and concave mirrors?
Convex = behind the mirror
Concave = in front of the mirror
What is the focal point?
Where light rays converge.
Define absorption
Light is absorbed by a median and converted to chemical energy.
Define reflection
Waves encounter a boundary where absorption cannot occur, and the waves are bounced off
Define efraction
The bending of light as it enders from one medium to another, causing it to speed up or slow down.
What determines which way light bends?
Density of new medium.
Low density -> high density = bends TOWARDS normal
High density -> Low density = bends AWAY from normal
What do white surfaces reflect?
All colour.
What do black surfaces reflect?
No colour. They absorb all colour.
How do you know the size of an angle in a refracted ray?
If it’s going from a low density to high density, it will be LARGER than the angle of incidence.
If it’s going from a high density to low density, it will be SMALLER than the angle of incidence.
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