Light and Sound Flashcards
What is a transverse wave?
A wave where the vibration of the particles is perpendicular to the direction of energy transfer.
What is a longitudinal wave?
A wave where the vibration of the particles is parallel to the direction of energy transfer.
What feature of the wave is shown on the diagram?
Amplitude.
What is amplitude?
The maximum displacement of particles from their rest position.
In a longitudinal wave, what are areas where the particles are pushed together called?
Compressions.
What is a louder sound associated with?
A higher amplitude.
What is a high-pitched sound associated with?
A higher frequency.
Give an example of a longitudinal wave.
Sound waves.
Give an example of a transverse wave.
Light waves.
What is an object that gives off light known as?
A luminous object.
How can we see non-luminous objects?
By the light they reflect.
What is it called when light hits an object and ‘stops’?
Absorption.
What is it called when light hits an object and bounces off?
Reflection.
What is a transparent material?
A material that lets light through without scattering.
What is an opaque material?
A material that does not let light pass through.
What is a translucent object?
An object that scatters light as it passes through.
What happens to the angle of incidence compared to the angle of reflection?
They are equal/the same.
What happens when the angle of incidence is greater than the critical angle?
All the light will be reflected (total internal reflection).
What is total internal reflection?
When all the light is reflected by a material.
Give two examples of where total internal reflection is found in real-life applications.
Periscopes and fibre-optic communications.
What is the name of the colored circle around the pupil?
Iris.
What is the purpose of the lens in the eye?
To focus light onto the retina.
What is the retina?
The light-sensitive layer at the back of the eye, made up of rods and cones.
What is the purpose of the optic nerve?
To carry messages from the retina to the brain.
What are the colors of the spectrum that make up white light?
Red, Orange, Yellow, Green, Blue, Indigo, Violet.
What does the color of light depend on?
The frequency of the wave.
Why do black objects appear black?
They absorb all colors of light and reflect none.
When red and green light is combined, what color is formed?
Yellow.
When red and blue light is combined, what color is formed?
Magenta.
When blue and green light is combined, what color is formed?
Cyan.
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.
Do light waves travel fastest through a solid, liquid, or gas?
Gas (light travels 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, so you may need to double the distance or halve the time provided.
What happens to the path of light when it enters a new substance?
It bends.
What is dispersion?
When light enters a prism and splits into the colors of the spectrum.
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 colors of light can our eyes detect?
Red, green, blue.
What happens to a wave when it changes speed?
It bends.
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
