CT3 Flashcards
Energy
The ability of an object (or living thing) to do work, perform an action.
How many types of energy stores are there?
6
What are the 6 different types of energy stores?
- Gravitational potential energy
- Chemical energy
- Kinetic energy
- Elastic energy
- Thermal energy
- Atomic (nuclear) energy
Gravitational potential energy
The higher above ground the object is, the more gravitational potential energy it has.
Chemical energy
The energy stored in substances and released (or absorbed) through chemical reactions.
Kinetic energy
Energy of movement.
Elastic potential energy
Stored in objects that regain their shape.
Thermal energy
The heat stored in an object.
Atomic (or nuclear) energy
Energy stored inside atoms.
Useful forms of energy
- Electricity
- Waves (light, sound, micro, x-rays)
- Magnetism
Law of conservation of energy
Energy is not created or destroyed, it is transferred
Dissipated
Spread out/lost
When does energy dissipate?
When it is transferred to the surroundings.
What do energy transfers provide?
Energy transfers can provide useful energy but also give out energy to the surroundings, which is not useful (wasteful).
Energy efficiency
Shows how much of the initial energy is transferred into useful energy.
Calculation for energy efficiency
useful energy transferred by the device / total energy supplied to the device
What are waves?
They are transfers of energy
What are the 2 types of waves
- Transverse
- Longitudinal
Transverse waves
The movement (wave) is perpendicular to the direction of travel.
Longitudinal
The movement is parallel to the direction of travel. Particles vibrate (energy is transmitted)
Electromagnetic waves (3)
- They do not need particles (material) to travel through.
- They transmit energy through force fields.
- Light waves, radio waves, microwaves.
What are sound waves and seismic waves both examples of?
Waves that can travel through a medium (material) by creating oscillations.
Period (/s)
Time taken for one complete wave to pass a point.
Frequency (/Hz, Hertz)
Number of waves per second.
Velocity (m/s)
Wave speed AND direction.
Amplitude (/m)
Half the distance the particles move as each wave goes past.
What do sound waves of low and high frequency have?
Low frequency = low pitch
High frequency = high pitch
What is the speed of the wave?
The distance traveled by energy in a certain time.
What are all the colours on the visible spectrum?
- Red
- Orange
- Yellow
- Green
- Blue
- Indigo
- Violet
What happens to light in secular reflection?
Light is reflected evenly.
What happens to light in diffuse reflection?
Light is scattered by a surface in lots of different directions.
What do sound waves create?
Pressure on the surfaces that they meet.
What are the 5 stages for sound from somewhere to reach the brain?
- Ear canal (sound wave incoming)
- Eardrum (very thin membrane vibrates)
- 2 tiny bones (amplify vibrations)
- Cochlea (generates impulses)
- Auditory nerve ( sends impulses to the brain)
Cochlea parts and functions
Fluid
Transmits the vibrations from the ear bones to the internal cochlea membrane.
Cochlea parts and functions
Membrane
Vibrates when waves from the fluid reach it.
Cochlea parts and functions
Hair cells
Detect vibrations of the membrane and convert them into signals.
Infrasound
Sound waves with frequencies less than 20Hz.
Ultrasound
Sound waves with frequencies higher than 20,000Hz.
Refraction
Waves changing direction when they go from one material to another.
Visible spectrum
Light perceived (seen) by the human eye.
What to all objects emit and why?
Infrared radiation due to their internal heat energy.
Microwaves infrared
Infrared = Frequency below red light.
Microwaves ultrasound
Ultraviolet = Frequency higher than blue light.
What are the units for measuring energy
joules (J)
What does a Sankey diagram show?
The amount of energy transferred. The width of the arrows represents the amount of energy in joules.
How do you calculate wave speed?
wave speed (m/s) = frequency (Hz) x wavelength (m)
