ΔE = mcΔθ for warming things up, and the required practical that measures a specific heat capacity, from method to graph.
What you will learn
- Use ΔE = mcΔθ to find energy, temperature rise, mass or c
- Plan the specific heat capacity practical and name its variables
- Find c from results or from the gradient of a temperature-time graph
Some things take more warming
The same energy that warms 1 kg of copper by 10 °C only warms 1 kg of water by about 1 °C.
Water has a much bigger specific heat capacity: the energy needed to raise the temperature of 1 kg of a substance by 1 °C.
change in thermal energy = mass × specific heat capacity × temperature change
ΔE = m c Δθ
Energy in J, mass in kg, c in J/kg°C, temperature change Δθ in °C. This one is on the equation sheet for AQA, Edexcel and OCR, and the paper gives you the value of c.
Some values: water 4200, olive oil about 2000, aluminium 900, concrete 880, iron 450, copper 385, all in J/kg°C.
Give equal masses the same energy and the material with the biggest c has the smallest temperature rise; the one with the smallest c warms up most.
The rest of this lesson and its 10 practice questions are locked.
In this lesson
- Some things take more warming
- Using the equation
- The required practical
- Try it: Your first heat calculation
10 practice questions, marked as you go; about 25 minutes in all.
Key terms
Biggest, Smallest, Independent variable, Dependent variable, Control variables, Gradient, Anomalous, Mean, Range, Higher
In this unit: Energy stores, transfers and efficiency
Energy stores and how energy moves between them, kinetic and potential energy, specific heat capacity, power, efficiency and the energy resources that make our electricity.