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Led by Lord Kelvin Simulacrum
Six tutorials covering AQA GCSE Physics §4.1 Energy — energy stores and systems, the algebra of kinetic, elastic, and gravitational energy, specific heat capacity, power, conservation and efficiency, and the national energy mix — taught by simulacra of the physicists who built the concept of energy itself.
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Led by Lord Kelvin Simulacrum
The question
What is a system, and what does it mean for the energy stored within it to change?
Territory
what a system is · the energy stores (kinetic, elastic, gravitational, thermal, chemical) · five canonical situations from the spec (projectile, moving object hitting an obstacle, object accelerated by a constant force, vehicle slowing, water brought to boil in an electric kettle) · three mechanisms of transfer (heating, work done by forces, work done when a current flows) · energy-transfer diagrams
Outcome
The student can identify the energy stores before and after a change, name the transfer mechanism, and produce a before-and-after diagram for any of the five canonical situations. (AQA 4.1.1.1)
Led by Hermann von Helmholtz Simulacrum
The question
If energy is stored, how do we put a number on it?
Territory
kinetic energy Ek = ½mv² · elastic potential energy Ee = ½ke² (within the limit of proportionality) · gravitational potential energy Ep = mgh · units and unit analysis · why kinetic and elastic energies scale as the square of their variable · why gravitational PE is linear in height · required practical 1 companion: the transfer of energy from gravitational to kinetic stores
Outcome
The student can apply the three equations correctly, reason about their units, and explain qualitatively why the squared forms appear in kinetic and elastic energy but not in gravitational potential. (AQA 4.1.1.2)
Led by James Prescott Joule Simulacrum
The question
Why does it take so much more energy to heat a kilogram of water than a kilogram of iron?
Territory
change in thermal energy ΔE = mcΔθ · specific heat capacity defined · molecular interpretation (atoms vibrate and store energy — more degrees of freedom, higher capacity) · required practical 1 (investigate the specific heat capacity of a material) · why water's specific heat capacity is unusually high · consequences for climate and cooking
Outcome
The student can apply ΔE = mcΔθ, carry out Required Practical 1 and state its sources of uncertainty, and explain qualitatively why different substances have different specific heat capacities. (AQA 4.1.1.3)
Led by James Watt Simulacrum
The question
Two electric motors lift the same crate to the same shelf. One takes five seconds, the other takes ten. What has that difference actually measured?
Territory
P = E/t · P = W/t · the watt and the kilowatt · the two-motor worked example from the spec · power ratings on everyday appliances (kettles, motors, bulbs) · the relationship between energy, power, and time
Outcome
The student can apply both power equations, convert freely between watts and kilowatts, and reason about the power of a machine from examples of the energy it transfers in a given time. (AQA 4.1.1.4)
Led by Sadi Carnot Simulacrum
The question
If energy cannot be created or destroyed, why does everything run down?
Territory
conservation of energy in a closed system · dissipation and "wasted" energy · lubrication and thermal insulation as ways to reduce unwanted transfers · thermal conductivity (qualitative — higher conductivity gives higher rate of energy transfer by conduction) · the rate of cooling of a building and the role of wall thickness and conductivity · required practical 2 (physics-only) — investigate the effectiveness of different thermal insulators · efficiency = useful output energy transfer / total input energy transfer · efficiency = useful power output / total power input · (Higher Tier) ways to increase the efficiency of an intended energy transfer
Outcome
The student can state the conservation law, identify dissipation with concrete examples, calculate efficiency as a decimal or percentage using either equation, and (Higher Tier) describe strategies for improving efficiency. The student can also carry out Required Practical 2 and discuss the effectiveness of different insulating materials. (AQA 4.1.2.1, 4.1.2.2)
Led by James Lovelock Simulacrum
The question
What powers the world today, and what constraints will shape the next fifty years?
Territory
the main energy resources on Earth (fossil fuels — coal, oil, gas · nuclear fuel · bio-fuel · wind · hydro-electricity · geothermal · the tides · the Sun · water waves) · renewable versus non-renewable · the three uses in the spec (transport, electricity generation, heating) · reliability of each resource · environmental impact of each resource · patterns and trends in use over recent decades · the boundary between what science can identify and what politics, economics, and ethics must decide
Outcome
The student can name the main energy resources, distinguish renewable from non-renewable, compare them on use and reliability, describe their environmental impact, and articulate why energy choices are partly scientific and partly political. (AQA 4.1.3)