Physics P1 Flashcards
What is the main form of heat transfer in solids ?
Conduction
What are the 3 ways heat energy can be transferred ?
Convection
Conduction
Radiation
What is the main form of heat transfer in liquid and gasses ?
Convection
T or F
Infrared can be emitted by solid
Liquid and gas
True
What is inflated radiation ?
Emission of electromagnetic waves - all objects are continually emitting and absorbing infared radiation
What is the Main form of heat transfer in solids?
Conduction
What is the main form if heat transfer in solid and liquid ?
Convection
What sort of objects can both absorb and emit infared radiation ?
Any objects can both absorb and emit infrared radiation whether or not conduction or convection are also taken place
the bigger the temperature difference between a body and its surrounding the faster energy is transferred by heating
True
How is infrared radiation emitted from objects?
All object emits infared radiation from the surface
Learn FACT :
A objects that’s hotter than it’s surrounding admits more radiation than it absorbs -Cool down
And an object at school it didn’t surrounded of little more radiation than it emits- warms up
The hotter an object is more radiation radiates in a given time
What factors does Radiation depend on?
Surface Colour and texture
Why does radiation depends on the surface:
Dark Matt surfaces absorb infrared radiation falling on them much better thanShiny surfaces than light, shiny surfaces such as gloss white or
Silver. They also admit much more IR at any given tempteture
Why is having a dark surface better for radiation
Dark Matt surfaces absorb infrared radiation falling on them much better thanShiny surfaces than light, shiny surfaces such as gloss white or
Silver. They also admit much more IR at any given tempteture
Why is light shiny surfaces bad for the absorbtion of radiation?
Like shiny surfaces reflect a lot of infrared radiation
Why is the inside of a vaccum flask got a light shiny surface?
Silver inner surfaces to keep heat in or out depending on whether it is storing hot or cold liquid
Why does solar hot water panels contain water pipes under a black surface?
The radiation from the sun is absorbed by the black surface heat the water in the pipes this water can be used for washing all pumped to radiators to heat the building
What are the three states of matter?
Give examples
Solid
Liquid
gases
Describe the positioning and the properties of the particles in a solid
There are strong forces of attraction which holds the particles close together in a fixed regular arrangement of particles have much energy so they can only vibrates about their fixed position
Describe the positioning and properties of the particles in a liquid?
There are Weaker forces of attraction between the particles and the particles are close together but can move past each other and form and in regular arrangement -they have more energy than the particles in a solid and they move in randon direction at low speed
Describe the properties and positioning of particles and gases
Almost no forces of attraction between the particles to particles have more energy then Those in liquids and solid and they are also free to move and travel in random directions at high speed
What is conduction of heat energy
It’s the process when vibrating particles pass on extra kinetic energy to neighbouring particles
Why are metals good conductors?
Metal contains free electrons
At the Hot end the electrons move faster and collides with other free electron transferring energy is about electrons then pass on their extra energy to other electrons
Because the electrons can move freely this obviously is a much faster way of transferring energy through the metal then slowly passing it between the neighbouring atom
This is by heat energy travel so fast through metals
What type of factors are better at IR?
.Matt dull surface area absorb infrared radiation better than light bright surface area
Why is light surface area are bad at absorbing IR?
This is because the light surface area are are better at reflecting eat rather than absorbing
What is conduction?
Conduction is in the process of vibrating particles passing on the extra kinetic energy to neighbouring particles
What is convection?
energetic particles moves from the hotter region to the colder region and and take heat energy with them
What is convection currents?
It’s a change in density
How does convection current account in a immersion heater?
The particles gain energy from the coils which then leads the liquid to expand and become less dense
The particles At the top will get some more energy so start moving around faster
As the hot water rises it displaces the cold water out of the way of making it sink towards the heater coils , overall the liquid particles contracts and becomes more dense and sinks
Cold water is heated by the coils and rises this is convection current
What is condensation?
Condensation is when gas turns into liquid
Describe the process in condensation?
When the gas calls the particles slow down and this kinetic energy
Attraction forces begins to pull the particles together at daily less kinetic energy
Eventually the gas condenses into liquid
What is in evaporation?
Is when the liquid turned into gas
Describe the process that happens in the evaporation
absorb heat energy okay kinetic energy and travel in randonm direction
Some of the particles will esccape from the surface area are leaving the remaining of the liquid to become
What factors will affect evaporation?
Big surface area
Higher tempteture
Wind/draft/fan (increases speed at which particles are made from the surface area so increase rate of evaporation
What does u values mean?
U values shows how fast heat can transfer through a material
True or faulse
Heat transfer faster through material with higher u value than through materials with low u value
True the better the insulator the Lower the lower uvalue
Why type of insulation would you have in your house
Cavity wall insulation Loft insulation Draught proofing Hot water tank jacket Thick curtain
What is specific heat capacity ?
How much energy stuff can be store
What are the formula for specific heat capacity ?
E= m x c x 0
Name 4 type of energy
Chemical energy
Gravitational potential
Elastic potential
Thermal energy
Name the three form of stored energy ?
- gravitational potential
- elastic energy
- chemical energy
What is the conservation of energy principle ?
Energy can be transferred usefully from to another stored or dissipated but never be created or destroyed
What do radiators have large surface. Area
This is because they have a large surface area to maximise the amount of heating transfer the bigger the surface the more infrared wave that can be emitted from the surface
Why does Cars and motorbike have engine which often has fins?
They increase the surface area say heat is radiated away quick call to the engine cools with quicker
Why does people use a ‘vaccum’ as insulation
Because it stopped all conduction and convection through the side
How does insulating foam work?
This minimises heat conduction and convection
Why does artic foxes have small ears ?
With a small surface area to minimise heat loss by radiation and conserve body heat
What does E = m x c x 0 mean
E= energy transferred in J
m= mass in kg
C = specific heat capacity
0 tempteture change
What is the formula for energy ?
Energy = power X time
What are non renewable energy ?
They will eventually run out
They do damage to the enviromental yet provide the most of our energy
What are renewable energy ?
They will never run out but don’t provide much energy and some of them are unreliable because they depend on the weather
What are example of non renewable energy ?
Coal
Oil
Natural Gas
Natural fuel
What are examples of renewable resources?
Wind Solar Tides Biofuels Geothermal Hydroelectric
