When the body is heated, the kinetic energy increases. What does it mean? Once the kinetic energy has increased, it means that the speed of propagation of molecules has also increased. In addition to speed, mass increases, which is in direct proportion to energy. Its increase is not significant, it can be seen only with very accurate measurements. In ordinary life, with an increase in temperature, changes are not noticeable at all. Since the increase in the speed of molecules compensates for the high speed of light.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.