When energy is needed in order for the reaction to happen, then that reaction is known as endotermic. When the reaction has as a result energy then it is exotermic. An example of an endotermic reaction would be photosynthesis, for an exotermic: combustion.
If we feel warm after exercising, it means that the temperature of the surroundings has increased. Therefore, heat is released from our body (energy transferred from the system to the surroundings) which means the internal energy of our body is decreased after exercising.
internal energy U is the sum of the kinetic energy brought about by the motion of molecules and the potential energy brought about by the vibrational motion and electric energy of atoms inside molecules in a system or a body with clearly defined limits. The energy contained in every chemical link is often referred to as internal energy. From a microscopic perspective, the internal energy can take on a variety of shapes. For any substance or chemical attraction between molecules.
Internal energy is a significant amount and a state function of a system. Specific internal energy, which is internal energy per mass of the substance in question, is a very intense thermodynamic characteristic that is often represented by the lowercase letter U. As a result, the J/g would be the SI unit for internal specific energy. The term "molar internal energy" and the unit "J/mol" might be used to describe internal energy that is expressed as a function of the quantity of a substance.
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B) <span>It is the instantaneous speed of the bike rider.</span>
