Physics - P1 Flashcards
1
Q
What is energy transferred and how do you calculate it? (SLH)
A
- energy is transferred when a substance changes state
- the amount of energy transferred depends on the mass and the specific latent heat
- energy transferred= mass x specific latent heat
2
Q
What is the definition of temperature and energy?
A
- temperature is a measure of hotness on an arbitrary scale, measured in celcius
- energy is a measure of energy transfer on an absolute scale measured in joules
3
Q
How can energy saving in a home be achieved by?
A
- double glazing
- cavity wall insulation
- draught strip
- reflecting foil
- loft insulation
- curtains
- careful designs
4
Q
How do you calculate efficiency?
A
- efficiency= useful energy output (100%) / total energy input
5
Q
What can energy transformations be represented by?
A
- sankey diagrams
6
Q
What do shiny surfaces reflect?
A
- they reflect infrared radiation to reduce energy transfer
7
Q
What are convection currents caused by?
A
- density changes
8
Q
What does trapped air reduce?
A
- it reduces energy transfer by convection
9
Q
What is a good insulater and reduces energy transfer by conduction?
A
- air
10
Q
What do warm and hot objects emit?
A
- infrared radiation
11
Q
What is infrared radiation used for?
A
- cooking
12
Q
What can microwaves be used for?
A
- cooking
- communication when transmitter and receiver are in line of sight
13
Q
What is laser light?
A
- it is single light and in phase
14
Q
What do laser light, visible light and infrared all have in common?
A
- use to send signals along optical fibres by total internal reflection
15
Q
What is energy transferred and how do you calculate it? (SHC)
A
- energy is transferred when a substance changes temperature
- the amount transferred depends on the mass, the temperature and the specific heat capacity
- energy transferred= mass x specific heat capacity x temperature change
