the strength and vitality required for sustained physical or mental activity.
changes in the levels of vitamins can affect energy and well-being
power derived from the utilization of physical or chemical resources, especially to provide light and heat or to work machines.
These include global warming, energy efficiency and renewable energy resources.
the property of matter and radiation that is manifest as a capacity to perform work (such as causing motion or the interaction of molecules).
a collision in which no energy is transferred