Science - Light and Sound Flashcards
Waves transfers _____________ but not ______________.
Energy, matter
Transverse wave - the _______________ of the particles is __________________ to the direction of energy transfer
vibrations, perpendicular
Longitudinal wave - the _______________ of the particles is __________________ to the direction of energy transfer
vibrations, parallel
What is the wavelength?
Distance between consecutive crests/troughs (transverse).
Distance between consecutive compressions/rarefactions (longitudinal).
What is the amplitude?
Distance from the equilibrium (rest position) to the crest/trough (transverse).
In a longitudinal wave, areas where the particles are pushed together are called _________________ and areas where the particles are spread out are called _________________
compressions, rarefactions
A louder sound will have a higher __________________.
amplitude
A high-pitched sound will have a higher _________________
frequency
Give 4 examples of longitudinal waves
sound, ultrasound, seismic waves, springs
Give 8 examples of transverse waves
light, radio, microwaves, infra-red, UV, X-ray, gamma ray, water waves
An object which gives off light is known as….
luminous
How can we see non-luminous objects?
because light is reflected off the object
When light hits and object and “stops” it is known as…
absorption
When light hits and object and bounces off it is known as…
reflection
A material that lets light through without scattering is known as…
transparent
What is an opaque material?
A material that does not let light pass through
An object that scatters light as it passes through is known as…
transluscent
How does the angle of incidence compare to the angle of reflection?
they are equal/the same
“If we are drawing a reflected ray, which step is missing
1. Extend the incident line to the surface.
2.
3. Measure angle of incidence.
4. Construct your angle of reflection.”
Draw on the normal line
What is refraction?
The change in direction of a wave when it changes speed.
When does refraction occur?
When a wave moves into a different substance
If the speed of a wave decreases as it moves into a new substance it will bend _____________ the normal
towards
If the speed of a wave increases as it moves into a new substance it will bend _____________ the normal
away from
When the angle of incidence is greater than the critical angle, what will happen to the light?
All the light will be reflected/total internal reflection.
If all the light is reflected with a material (e.g. a piece of glass), what is this known as?
Total internal reflection
Give 3 examples of where total internal reflection is found in real-life applications
Periscopes, internal cameras, fibre-optic communications
What is the name of the coloured circle around the pupil. It controls the size of the pupil
Iris
What is the purpose of the lens in the eye?
To focus light onto the retina
What do you call the black part of the eye? It is the opening that lets light in
Pupil
What is the retina?
Light-sensitive layer at the back of the eye, made up of rods and cones
What is the purpose of the optic nerve?
Carries messages from the retina to the brain.
Why do we end up with an inverted image formed on our retina when we look at an object?
Because light is refracted by the cornea and lens in our eye.
What three colours of light can our eyes detect?
red, green, blue
What are the colours of the spectrum that make up white light?
Red, Orange, Yellow, Green, Blue, Indigo, Violet (Richard Of York Gave Battle In Vain)
The colour of a light depends on what feature of a wave?
Frequency
When light enters a prism it splits into the colours of the spectrum, what do we call this effect?
Dispersion
Why does a blue object appear blue when a white light is shone upon it?
It reflects blue light. It absorbs all other colours of light.
Why do black objects appear black?
They absorb all colours that are shone on them. No light is reflected.
When red and green light is combined, what colour is formed?
yellow
When red and blue light is combined, what colour is formed?
magenta
When blue and green light is combined, what colour is formed?
cyan
If a sound is becoming lower pitched, what is decreasing?
The frequency
If a sound is becoming lower in volume, what is decreasing?
The amplitude
What formula can we use to calculate the speed of sound?
speed = distance/time
Do sound waves travel fastest in solid, liquid or gas?
Solid (more particles)
Do light waves travel fastest through a solid, liquid or gas?
Gas (fastest through a vacuum)
When calculating the speed of sound using an echo, what must you remember
The echo travels to an object and back again (you may need to double the distance or halve the time provided)
