Diffusion phenomenon: When different substances come into contact with each other, they enter each other (molecules move irregularly and there are gaps between molecules)

molecular kinetic theory

Concept: The sum of the kinetic energy and molecular potential energy of all molecules in an object.

An object has internal energy at any time

Size: related to temperature, mass, volume, type and state of matter

Change: Work and Heat Transfer

Concept: In the process of heat transfer, the amount of energy transferred is called heat

It is a process quantity. The object absorbs heat and the internal energy increases. The object releases heat and the internal energy decreases (ice melts, the temperature remains unchanged, but the internal energy increases).

Concept: The amount of heat absorbed when the temperature of a unit mass of a certain substance increases by 1°C (or the heat released when the temperature decreases by 1°C)

It is a property of the substance itself and has nothing to do with shape or quality.

Unit: J/(kg×℃)

How to calculate heat: Q=cmΔt

Water has a large specific heat capacity and is widely used in

The greater the specific heat capacity, the stronger the heat absorption capacity, and the more difficult it is to change the temperature.

Type: steam engine, internal combustion engine, steam turbine, jet engine

internal combustion engine

Heat engine efficiency

During the energy conversion process, the energy form changes

During the energy transfer process, the energy form remains unchanged

Law of conservation of energy: Energy will neither disappear nor be created out of thin air. It will only be converted from one form to other forms, or transferred from one object to another. In the process of transformation and transfer, energy The total amount remains the same.