Buildings Flashcards
(7 cards)
1
Q
The specific heat capacity of water is 4181 j/kg/ degrees and that of lead is 128 J/kg/ degrees. This means…
A
More energy is needed to heat water than it is to heat the same mass of lead
2
Q
U-values means
A
The measure of effectiveness of a material as an insulator in buildings
3
Q
Payback time=
A
Payback time (years) = cost of installation(£) divide by savings per year in fuel costs (£)
4
Q
Advantages of solar panels
A
- solar energy is RENEWABLE
- no harmful polluting or gases are produced
5
Q
Disadvantages of solar panels
A
- can only produce very hot water in very sunny climates
- they don’t work overnight
6
Q
Unit of energy and temperature
A
Energy = J (joules)
Temperature = degrees C
7
Q
Specific heat capacity means
A
The substance is the amount of energy needed to change the temperature of 1kg to 1 degree
