Thermodynamics: heat, work and what is possible

Bring with you: Add, subtract, multiply and divide signed numbers; use decimals and simple fractions. Read a labelled scale and substitute values into a short equation. A calculator is welcome.

Why can melting ice absorb energy without warming? Why does a pump warm up, and why can no engine turn all incoming heat into work? Build the models to explain these everyday changes and judge a thermal design.

Begin with two cups and a thermometer. Progress through heating and gas measurements to energy accounts, engines, refrigeration and entropy. Finish by checking a thermal shelter design.

By the end, you can…

• Use temperature readings to tell when objects will warm or cool each other.
• Explain what changes when objects warm or cool.
• Work out how much energy will warm a material by a chosen amount.
• Predict warming, mixing and melting with the right energy model.
• Read a gas’s pressure, volume and temperature, using the right units.
• Relate gas measurements and calculate energy transferred by a piston.
• Keep track of energy entering and leaving a system.
• Track signed energy transfers through different processes and cycles.
• Find how much of an engine’s incoming heat becomes useful work.
• Check what useful output a thermal machine can deliver.
• Check which way a heat transfer can happen by itself.
• Use entropy and connected models to judge real thermal designs.

For another Course

• Calculus, microscopic statistical counting, variable heat-capacity integrals and detailed entropy tables.
• Chemical reactions, enthalpy and steady-flow engineering devices; real-gas equations and detailed engine design.
• Molar ideal-gas calculations using pV = nRT; this introduction treats a fixed amount with pV/T constant.