#3.1
Recall and use the equation to calculate the change in gravitational PE when an object is raised above the ground:
change in gravitational potential energy (joule, J) = mass (kilogram, kg) × gravitational field strength (newton per kilogram, N/kg) × change in vertical height (metre, m)
\(\Delta GPE = m × g × \Delta h\)
#3.2
Recall and use the equation to calculate the amounts of energy associated with a moving object:
kinetic energy (joule, J) = \(\frac{1}{2}\) × mass (kilogram, kg) × (speed)2 ((metre/second)2, (m/s)2)
\(KE = \dfrac{1}{2} × m × v^2\)
#3.3
Draw and interpret diagrams to represent energy transfers
#3.4
Explain what is meant by conservation of energy
#3.5
Analyse the changes involved in the way energy is stored when a system changes, including:
a) an object projected upwards or up a slope
b) a moving object hitting an obstacle
c) an object being accelerated by a constant force
d) a vehicle slowing down
e) bringing water to a boil in an electric kettle
#3.6
Explain that where there are energy transfers in a closed system there is no net change to the total energy in that system
#3.7
Explain that mechanical processes become wasteful when they cause a rise in temperature so dissipating energy in heating the surroundings
#3.8
Explain, using examples, how in all system changes energy is dissipated so that it is stored in less useful ways
#3.9
Explain ways of reducing unwanted energy transfer including through lubrication, thermal insulation
#3.10
Describe the effects of the thickness and thermal conductivity of the walls of a building on its rate of cooling qualitatively
#3.11
Recall and use the equation:
\(\text{efficiency} = \dfrac{\text{useful energy transferred by the device}}{\text{total energy supplied to the device}}\)
#3.12
Explain how efficiency can be increased
#3.13
Describe the main energy sources available for use on Earth (including fossil fuels, nuclear fuel, bio-fuel, wind, hydro-electricity, the tides and the Sun), and compare the ways in which both renewable and non-renewable sources are used
#3.14
Explain patterns and trends in the use of energy resources