LECTURE 24 ENERGY Work- Application of force through a distance . Energy- The capacity to do work . Power- Rate at which work is done or rate of flow of energy. Units of energy – Joule- Amount of work done when a force of 1 Newton is exerted over 1 meter (or about 0.238cal). – Calorie - Amount of energy necessary to heat 1 gram of water 1 o C. – Watt - 1 joule/sec On average, each person in the U.S. and Canada uses more than 300 GJ of energy annually . In poorest countries of the world, each person generally consumes less than one GJ annually. Richest 20 countries consume annually : nearly 80% of natural gas, 65% of oil, and 50% of coal production. Industry- 33%, Residential , commercial buildings- 38%, Transportation- 27%. About 50% of all the energy in primary fuels is lost during conversion to more useful forms (eg, 2/3 energy of coal lost in thermal conversion, ie, combustion), while being shipped to the site of end use, or (eg, 10% energy lost in transmission lines) during
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