Physics - unit 1 - topic 1: Heating processes

Phase changes and energy conservation

Explain, in terms of the internal energy of a system and the kinetic particle model of matter, why the temperature of a system remains the same during the process of state change.

During a state change, the temperature of a system remains constant because the thermal energy supplied is utilized to overcome intermolecular forces, which increases the potential energy without raising the kinetic energy. This effect is referred to as latent heat.

Describe the concept of specific latent heat

Specific latent heat is the amount of thermal energy required to change the state of a unit mass of a substance without changing its temperature, influencing potential energy instead of kinetic energy.

Describe the concept of thermal equilibrium in terms of the temperature and average kinetic energy of the particles in each of the systems.

Thermal equilibrium occurs when two or more systems are at the same temperature resulting in no net heat transfer between them. this means the average kinetic energy of the systems are equal.

Explain the process in which thermal energy is transferred between two systems until thermal equilibrium is achieved, and recognise the relevance of this to the laws of thermodynamics.

Conduction, convection and radiation

Explain how a system with thermal energy has the capacity to do mechanical work

By transferring heat to a working substance

first law of thermodynamics

The change in the internal energy of a system is equal to the energy added or removed by heating plus the work done on or by the system, this is a consequence of the law of conservation of energy

Describe the concept of efficiency

the measure of how well a system converts input energy into useful output energy. How much energy is lost to the environment, the lower, the more efficient the system.

What is the relationship between heat and temperature change

Proportional