note on heat and cold
Answers
Answer:
Heat, or thermal energy is the sum of the kinetic energy of atoms or molecules. In thermodynamics, heat means energy which is moved between two things, when one of them has a higher temperature than the other thing. ... When an object is heated, its internal energy can increase to make the object hotter.
The common cold, also known simply as a cold, is a viral infectious disease of the upper respiratory tract that primarily affects the respiratory mucosa of the nose, throat, sinuses, and larynx. Signs and symptoms may appear less than two days after exposure to the virus.
Explanation:
With the increase in the temperature of a body, the vibrations of molecules or atoms increase. These vibrations are then transferred from one part of the body to another. The measure of energy with which the molecules vibrate in a system is termed as heat stored in that object.
As per the definition of heat, it is defined as the flow of energy from a warm to a cooler object. The direction of flow of the heat energy takes from the substance of higher temperature to the substance of lower temperature. This is because the molecules are vibrating faster and transfer their energy to the molecules vibrating slower. The vibrational energy is also termed as its heat content. The heat content in the body makes it hot or cold. Greater the heat content, hotter will be the body.
A substance may absorb heat without an increase in temperature by changing from one physical state to another. In the process of melting, the substance is changed from solid to liquid. In the process of sublimation, solid is converted into the vapour state. In the process of boiling, the liquid is converted to vapour. Heat is a form of energy that can be converted into work. Amount of energy is expressed in units of work. It is expressed in joules, foot-pounds, kilowatt-hours, or calories.
Heat as a form of energy can be converted to other forms of energy. For example, in motorized vehicles, heat is converted to mechanical energy. In electric bulbs, it is converted to light energy. In thermal power plants, it is finally converted to electrical energy.