Energy is changed from one form to another with no net loss or gain.
a) sometimes true
b) always false
c) always true

The correct answer is C) Always true

Explanation:

The law of conservation of energy states that energy cannot be created or destroyed. That implies that the total energy of a isolated system is constant. The energy can change from one form to another with not net loss or gain. For example, in a washing machine, the electrical energy supplied is transformed to mechanical energy which moves the tub. This law constitutes a fundamental principle of thermodynamics and physics, so it is always true.

compass can be used day and night, cloudy or sunny