Light and Sound Flashcards
Describe Light as a form of energy; identify light sources and opaque objects
Light is the only form of energy that is visible to the human eye. Light consists of photons, which are produced when an object’s atoms heat up. When light passes through an object - most of the light is either reflected by or absorbed by the object. For Opaque objects, it’s absorbed.
State the properties of light
The properties of light are its wavelength, frequency, energy and speed
Explain the Law of Reflection
The angle between the incident ray and the normal is called the angle of incidence. The angle between the reflected ray and the normal is called the angle of reflection.
Use the Law of Reflection with Flat and Curved mirrors
Convex Mirrors - A convex mirror is also known as diverging mirror as it diverges the incident rays after reflection
Concave Mirrors - A concave mirror is also known as converging mirror as it converges the incident rays after reflection
Explain refraction in terms of change in light speed
Refraction is the bending of light when it enters a medium where its speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray towards the normal. As the light ray leaves the slower medium, it will travel at same angle it entered it on.
State that light travels at different substances
The substance where the particles are ‘packed’ differently depends on what state they are in. It is the way these substances are ‘packed’ that affects the speed at which light can move through them.
Identify Total Internal Reflection
Diamonds are one of the densest substances in the world. Light is able to enter a diamond but is reflected off multiple times before it can escape. This is why diamonds tend to “sparkle”
Total Internal Reflection is the light completely trapped within a medium
State the application of internal reflection
Light is bounced along the cables carrying information.
Describe white light as a mixture of different colours
White light is a mixture of coloured lights
Explain coloured surfaces due to the wavelengths they reflect
Some of the colours of light are absorbed. Only the colours that are not absorbed are reflected and enter our eyes. Objects that reflect all the colours in white light look white because all the colours get back to your eye. Opaque colours are the ones that aren’t reflected rather than absorbed
Cornea (Eye)
Clear tissue that covers the front of the eye
Pupil (Eye)
Opening through which light enters the eye
Iris (Eyes)
Coloured part of the eye, ,controls the amount of light entering the eye
Lens (Eyes)
Focuses light on the retina.
Retina (Eyes)
Layer of light-sensitive cells in the back of the eye which respond to light
Optic Nerve (Eyes)
The bundle of nerve fibres that carry information to the brain
How is Camera similar to the Human Eye?
Controls amount of light entering
How is Aperture similar to the Pupil?
Opening to the inside
How is Diaphragm similar to the Eyelid?
Opens and closes to let in light
How is Lens similar to the Cornea and Lens?
Focuses the image
How is Film similar to the Retina?
Light-sensitive part that captures the image
Explain Binocular Vision?
What we see is the result of signals sent from the eyes to the brain. Usually, the brain receives signals from both eyes at the same time. The brain is able to use these two perspectives to judge distances and coordinate movements in space and time.
What is Sound?
Sound is created when something vibrates and sends waves of energy into our ears. The vibrations travel through the air or another medium to the ear. The stronger the vibrations, the louder the sound.
How is Sound Formed?
A sound is a form of kinetic energy. When sound is created particles vibrate sending waves of energy to the ear.
3 Differences between Light and Sound
Sound Waves
- Sound Waves need a material medium for their propagation
- Sound waves are longitudinal
- Sound waves have a very low speed of about 350m/s in the air at room temperature
Light Waves
- Light waves do not need a material medium for their propagation. They can travel even through a vacuum
- Light waves are transverse
- Light waves have a very high speed at 3 x 10 m/s in a vacuum or air
Explain how a frequency and wavelength of a sound is related
Frequency is the number of waves per second. In other words the shorter the wavelength, the higher the frequency. While Wavelength is measured in decibel. The bigger the amplitude the louder the sound.
Explain how a frequency and wavelength of a sound is related
Frequency is the number of waves per second. In other words the shorter the wavelength, the higher the frequency. While Wavelength is measured in decibel. The bigger the amplitude the louder the sound.
Pinna
It collects sound waves and channels them into the ear canal
Auditory Canal
It is an entryway into the ear
Ear Drum
It collects sound waves and channels them into the ear canal
Malleus
Functions to transmit vibration from the ear drum to the inner ear
Incus
The incus transmit vibration from the Malleus to the Stapes
Stapes
Crosses the middle ear and transmit vibrations caused by sound waves from the eardrum membrane to the liquid of the inner ear
Semicircular Canal
It’s what keeps you balance when hearing
Cochlea
Transform the vibration of the cochlear liquids and turns into neural signals
Auditory Nerve
Is responsible for hearing
