P1 - Energy For The Home Flashcards
What is heat?
Heat is the measure of energy.
What is temperature?
Temperature is a measure of hotness (heat)
What is specific heat capacity?
It is how much energy it takes to increase a objects of 1kg overall temperature for 1 degree centigrade
What is the equation for specific heat capacity?
Energy = Mass x Specific heat capacity x Temperature change
Which direction does heat transfer?
Hot to cold
What is specific latent heat?
This is the energy needed to change the state of 1kg without the temperature changing.
What is the equation for specific latent heat?
Energy = mass x SLH
What is condition?
This mainly occurs in solids and the heat is passed on by vibrating particles passing the KE on
What is convection?
This happens in liquids and gases and when the particles rise when heated then cool and sink
What makes objects emit and absorb more energy?
- Rough surfaces
- Matt and darker colours
What are some ways of saving energy in a home?
- loft insulation
- double glazing
- thick curtains
- wall insulation
What can show you the efficiency of your home?
Thermograms (white = warmest and black = coldest)
How do you work out the efficiency?
Efficiency = useful energy output / total energy input (x100)
What happens to the energy input of machines?
Some is used as a useful energy output and some is waste energy
What diagram can you use to show what happens to the energy of an application?
Sankey diagram
What is the wavelength?
This is from one crest to another
What is the amplitude?
From the rest position to the crest.
What is the equation for wave speed?
Speed = frequency x wavelength
Why is light reflected?
So you can see objects
What is the law of the reflection?
Angle of incidence = Angle of reflection
What is total internal reflection?
If the total internal reflection is greater than the critical angle light will be reflected
What is diffraction?
This is the spreading out of waves when they go through a gap
What is refraction?
This is when light hits a denser material at an angle, changing its angle
What characteristics do lasers have?
- Monochromatic (in one colour and phase)
- Intense beat (increase in amplitude with same wavelength)
- Low divergence (very small ray)
How do lasers read digital information?
In the CD there are lands and pits which represents on and off and the laser can detect this.
How can infrared be used to control electrical equipment?
This sends impulses to the equipment giving instructions on what to do
How are radio waves used for communications?
The short wave radio waves reflect of the ionosphere
The long wave radio waves diffract around the earth
They can refract off the ionosphere making them travel further
How are microwaves used for communication?
They are used for satellite communication because they can easily go through clouds and water vapour
What are EM receivers?
These collect the information
What are the two types of signals?
Analogue and digital
What is the interference like on analogue signals?
There is much more as there is able to be much more on a wave
What is the interference like on digital signals?
There is less interference because there is only on and off and it’s only on them
What radiation causes skin cancer?
Ultraviolet radiation
What does the sun protection factor show (SPF)?
If it is FPS 15 it means that you will last 15 times longer
How is the ozone layer broken down?
CFCs from fridges and aerosols break down ozone to oxygen which means ionising radiation is let in
Where is there a hole in the ozone layer?
Over Antarctica
What do earthquakes cause?
Seismic waves
What are long longitudinal waves?
P waves are the vibration that travel the same way as the wave direction
What are transverse waves?
S waves that vibrations are at right angles to the wave direction
What are the characteristics of p waves?
Travel fast so they can travel through solids and liquids
What are the characteristics of S waves?
They are slow meaning they can only travel through solids
