Citations:work


 * 2012 March 22nd, David Blockley, Engineering: A Very Short Introduction (309),, ISBN 9780199578696, chapter 2: “The age of gravity – time for work”, page 20:
 * In STEM (science, technology, engineering, and mathematics), work is defined precisely and objectively so that it is unbiased and independent of personal opinions. Work is the product of force and distance. So if you lift a mass of 1 kilogram (which has a weight of approximately 10 newtons) through 2 metres, then the work you do is 20 newton metres, or 20 joules. In the past, before the widespread adoption of SI units, the work that engines were capable of doing was compared with the work that horses could do – hence the term ‘horsepower’. Various people came up with various equivalencies, but the modern agreed definition is that 1 horsepower is 746 joules per second or 746 watts. When we feel energetic, we feel ready to work – so energy is the capacity to do work and is also measured in joules. Power is the rate of expending energy or doing work. It is measured in joules per second or watts.