lämpömäärästä

Lämpömäärä, often referred to as heat energy, is the total thermal energy contained within a substance. It is a measure of the kinetic energy of the atoms and molecules within a system. When heat is transferred into a substance, its internal energy increases, leading to a rise in temperature or a change in its phase, such as melting or boiling. Conversely, when heat is removed, the internal energy decreases, resulting in a drop in temperature or a phase transition in the opposite direction.

The unit of heat energy in the International System of Units (SI) is the joule (J). However, the calorie (cal) is also commonly used, particularly in contexts related to food and nutrition. One calorie is defined as the amount of heat energy required to raise the temperature of one gram of water by one degree Celsius. The relationship between joules and calories is approximately 1 calorie = 4.184 joules.

The amount of heat energy required to change the temperature of a substance is determined by its mass, its specific heat capacity, and the magnitude of the temperature change. Specific heat capacity is a material property that indicates how much heat energy is needed to raise the temperature of one unit of mass of the substance by one degree. Different substances have different specific heat capacities; for example, water has a relatively high specific heat capacity, meaning it can absorb or release a large amount of heat without significant temperature changes.