25. a) Explain the law of conservation of energy.
b) Give one example of each energy transformation:
1. Heat energy to mechanical energy
2. Mechanical energy to electrical energy.
Answers
Answer:
a. the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. This law means that energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another. For instance, chemical energy is converted to kinetic energy when a stick of dynamite explodes. If one adds up all forms of energy that were released in the explosion, such as the kinetic energy and potential energy of the pieces, as well as heat and sound, one will get the exact decrease of chemical energy in the combustion of the dynamite. Classically, conservation of energy was distinct from conservation of mass; however, special relativity showed that mass is related to energy and vice versa by E = mc2, and science now takes the view that mass–energy as a whole is conserved. Theoretically, this implies that any object with mass can itself be converted to pure energy, and vice versa, though this is believed to be possible only under the most extreme of physical conditions, such as likely existed in the universe very shortly after the Big Bang.
b. 1. Steam Engine
Steam engines run on steam which is heat energy. This heat energy is converted into mechanical energy that is used to run locomotives. It is an example of conversion of heat energy into mechanical energy
2. wind turbines work to produce electricity
a) law of conservation state that energy can niether be created not be destroyed
b)the lighting strike on a tree is an example of electrical energy being transfromed into heat or thermal.energy .
1) a steam engine converts the heat energy of stem into mechanical energy.
2)a generator converts mechanical energy into electrical energy .while a mirror thus the opposite ......