P1.1.4 - AQA GCSE Physics Unit 1

P1.1.4	Heating and insulating buildings
	a) U-values measure how effective a material is as an insulator.	Knowledge of the U-values of specific materials is *not* required, nor is the equation that defines a U-value.	Mathematically minded students will prefer to be given the equation and have it explained - this will help them remember whether a U-value needs to be high or low.
	b) The lower the U-value, the better the material is as an insulator
	c) Solar panels may contain water that is heated by radiation from the Sun. This water may then be used to heat buildings or provide domestic hot water.		The link covers solar cells and panels - students often confuse the two!
	The specific heat capacity of a substance is the amount of energy required to change the temperature of one kilogram of the substance by one degree Celsius. E = m x θ x c	E is energy transferred in joules, J m is mass in kilograms, kg θ is temperature change in degrees Celsius, °C c is specific heat capacity in J / kg °C