Science Test Physics Flashcards
(23 cards)
What is a wave?
A wave is the transport of energy. Waves transport energy through the vibration of a medium, but the medium itself does not move with the wave.
What is a medium?
A substance through which a wave is moving.
What are the wave types and give examples?
Mechanical waves are waves that cause particles in the medium to vibrate. Examples - waves on a string, water waves, sound waves, earthquake waves. Electromagnetic waves do not require particles, but rather cause fields to vibrate. Examples - radio waves, microwaves, light waves, UV radiation, X-rays.
What is amplitude - symbol and unit?
The furthest particles move away from the normal resting position is called the amplitude. It is given the symbol A and is measured in meters.
What is wavelength - symbol and unit?
The wavelength is the distance between two crests or two troughs. It is given the symbol λ (lambda) and is measured in meters.
What is period - symbol and unit?
The period of a wave is the time taken for a wave to complete 1 cycle. The period of a wave is given the symbol T and is measured in seconds (s).
What is frequency - symbol and unit?
The frequency of a wave is the number of wavelengths that pass through a point every second. The symbol for frequency is f, and the unit is Hz (Hertz).
What is wave speed - symbol and unit?
The wave speed is a measure of how fast the energy is being transported through the medium. Wave speed is given the symbol v and is measured in m/s.
How do sound waves travel?
The vibrating source causes air particles to vibrate. The vibrating air particles cause adjacent air particles to vibrate and so on. In this way, energy is transported by vibrating air particles (a sound wave).
What is the sound amplitude?
The amplitude of a sound wave is determined by the amount of air pressure. The higher the amplitude, the higher the volume of the sound. Volume is measured in decibels.
What is the sound frequency?
The pitch of a sound is how high or low the sound is. It is determined by the frequency of the sound wave. The higher the frequency, the higher the pitch.
What is light?
Light is a form of energy that is transferred as a wave.
Where does light come from?
All light comes from a transfer of energy from another form. Luminous objects create light. Reflective objects reflect light that hits them.
What type of wave is light?
A light wave is a transverse wave consisting of oscillations in the electric and magnetic fields. Light does not require a medium to travel through.
How does light travel?
Light travels in a straight line until it strikes an object.
How do shadows form?
Shadows are formed when light strikes an opaque object and blocks the light rays.
What is the speed of light and unit?
Light travels at 300 000 000 meters every second! This is the fastest that anything can travel in the universe. We give this value the symbol, c.
How to time travel of a given distance?
To calculate the time to travel a given distance, divide the distance by the velocity.
Explain light intensity?
The amplitude of a light wave determines how bright the light is. We call the brightness of light the light intensity. Light intensity decreases as the distance from the light source increases.
Explain the visible spectrum?
The visible spectrum contains a range of wavelengths, each corresponding to a different color of the rainbow.
Explain colour of an object in light of a specific colour?
When light of a specific colour is shone on an object: A white object will appear as the same colour as the light since it reflects all wavelengths. A black object will appear black since it absorbs all wavelengths. A coloured object will appear as a colour that is dependent on both the incident light and the colour of the object
What is additive mixing of colours?
Additive mixing occurs when light of different wavelengths of light are combined. The primary colours of additive mixing are Red, Green, and Blue. Secondary colours results from a mixing of primary colours. Mixing all three primary colours results in white light.
What is heat absorption?
Dark colours become hotter quicker because they absorb more wavelengths of light. White objects reflect all wavelengths of light so they do not heat up quickly. Black objects heat up very quickly because they absorb all wavelengths of light.
