'''Effort''' is the expenditure of physical and/or mental powers which are required to produce something worthwhile, often referring to hard [[work]], great [[insight]] or overcoming difficulty.
It may also apply to the product of the work, so that a [[teacher]] may say "that essay was a great effort''
In [[classical mechanics]], effort is the [[force]] or[[ energy]] that is applied to a [[machine]] for the accomplishment of useful work.