Specific heat capacity - Energy and heating - AQA - GCSE Physics (Single Science) Revision - AQA - BBC Bitesize.pdf

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Home News Sport Earth Reel Worklife Home Learn Study support Careers Parents Trending More My Bitesize GCSE AQA Energy and heating - AQA Specific heat capacity Energy is transmitted by conduction, convection or radiation.The conductivity of materials can be compared by examining the time taken to transmit energy through them. Part of Physics (Single Science) Energy Save to My Bitesize Revise Audio Test Pages Energy and heating Thermal conductivity Investigating methods of insulation - materials Investigating methods of insulation - thickness  Specific heat capacity Practical - measuring specific heat capacity Specific heat capacity Heating materials When materials are heated, the molecules gain kinetic energy and start moving faster. The result is that the material gets hotter. Key fact Temperature is a measure of the average kinetic energy of the molecules. Different materials require different amounts of energy to change temperature. The amount of energy needed depends on: the mass of the material the substance of the material ( specific heat capacity ) the desired temperature change It takes less energy to raise the temperature of a block of aluminium by 1°C than it does to raise the same amount of water by 1°C. The amount of energy required to change the temperature of a material depends on the specific heat capacity of the material. Heat capacity The specific heat capacity of water is 4,200 Joules per kilogram per degree Celsius (J/kg°C). This means that it takes 4,200 J to raise the temperature of 1 kg of water by 1°C. Some other examples of specific heat capacities are: Material Specific heat capacity (J/kg/°C) Brick 840 Copper 385  Material Specific heat capacity (J/kg/°C) Lead 129 Lead will warm up and cool down fastest because it doesn’t take much energy to change its temperature. Brick will take much longer to heat up and cool down. This is why bricks are sometimes used in storage heaters as they stay warm for a long time. Most heaters are filled with oil (1,800 J/kg°C) or water (4,200 J/kg°C) as these emit a lot of energy as they cool down and, therefore, stay warm for a long time. Key fact The specific heat capacity of a material is the energy required to raise one kilogram (kg) of the material by one degree Celsius (°C). Learn more about specific heat capacity in this podcast Listen to the full series on BBC Sounds. 08:11  Open Transcript Calculating thermal energy changes The amount of thermal energy stored or released as the temperature of a system changes can be calculated using the equation: change in thermal energy = mass × specific heat capacity × temperature change ΔEt = m × c × ΔΘ This is when: change in thermal energy (ΔEt) is measured in joules (J) mass (m) is measured in kilograms (kg) specific heat capacity (c) is measured in joules per kilogram per degree Celsius (J/kg°C) temperature change (∆θ) is measured in degrees Celsius (°C) Example Sadie is experimenting with a model steam engine. Before the 0.25 kg of water begins to boil it needs to be heated from 20°C up to 100°C. If the specific heat capacity of water is 4,180 J/kg°C, how much thermal energy is needed to get the water up to boiling point? Et = m c Δθ Et = 0.25 × 4, 180 × (100 − 20) Et = 0.25 × 4, 180 × 80 Et = 83, 600 J Question How much thermal energy does a 2 kg steel block (c = 450 J/kg°C) lose when it cools from 300°C to 20°C?  Show answer Question How hot does a 3.5 kg brick get if it’s heated from 20°C by 20,000 J (20 kJ)? Show answer Previous page Next page Investigating methods of Practical - measuring specific insulation - thickness heat capacity More guides on this topic Changes in energy stores - AQA Work, power and efficiency - AQA Energy demands - AQA Sample exam questions - energy - AQA Related links Physics: Exam-style questions Bitesize revision podcasts Personalise your Bitesize! Language: Jobs that use Physics BBC Earth English Isaac Physics Quizlet Revisio Subscription  Tassomai Subscription Science Museum Home Earth Travel Music Sounds News Reel Culture TV Sport Worklife Future Weather Terms of Use About the BBC Privacy Policy Cookies Accessibility Help Parental Guidance Contact the BBC Get Personalised Newsletters Why you can trust the BBC Advertise with us Do not share or sell my info © 2024 BBC. The BBC is not responsible for the content of external sites. Read about our approach to external linking.