Question

Do all changes involve exchange of energy? Give examples supporting your answer.

Answer 1

Yes, all changes involve exchange of energy. Energy is either absorbed or released during changes. Energy is always present and it only takes different forms without which, no change can happen.
Example:

• When ice is melted, solid state changes to liquid. Here, energy is supplied in the form of heat. This heat energy is absorbed by the ice cubes and they start melting. Hence, ice cubes (solid state) changes to water (liquid state) by exchange of energy.
• Breaking a wooden log with axe by a person. Here, the energy is exerted by the person through axe on the wooden log. Thus, energy is transformed from the person to axe and then to the wooden log. Hence, exchange of energy causes the breaking of wooden log.