How is energy measuredPosted by monsterguide
How is energy measured
What is energy?
Energy is the ability to do work and results in a change. It is a very commonly used word in our everyday lives.
Different Forms of Energy
Energy exists as different forms, and they are broadly categorized as potential and kinetic energy.
Energy that is possessed by virtue of its position is called potential energy.
Forms of Potential Energy
Chemical Energy is the energy that holds atoms and molecules by bonds and is stored in these bonds. Energy from biomass, natural gas, and petroleum are examples of stored chemical energy.
Mechanical Energy is energy, which is stored in objects by the application of a force. Stressed rubber strips and compressed springs store mechanical energy.
Nuclear Energy is that energy which is stored in the nucleus; this energy holds the nucleus together. The same energy can be released by fusion or fission of nuclei. Nuclear power plants are examples of fission when they split the nuclei of uranium atoms. In the sun, nuclear fusion happens wherein nuclei of hydrogen atoms are fused.
Gravitational Energy is another form of potential energy. Water in a reservoir behind the dam possesses gravitational potential energy.
Energy that is possessed by virtue of motion is called kinetic energy.
Moving electrons, atoms, molecules and objects possess kinetic energy.
Forms of Kinetic Energy
Electrical Energy is resultant of movement of electrical charges. The movement of charges through a cable is called electricity. Lightning is an example of electrical energy.
Radiant Energy is an electro-magnetic form of energy that travels as transverse waves. Energy of visible light, x-rays, gamma rays and radio waves are some examples of radiant energy.
Thermal Energy is a form of energy given out as heat due to internal vibration and displacement of atoms and molecules within substances. An erupting volcano is a form of thermal energy.
Wind is the best example of Motion Energy.
Sound is another form of kinetic energy where there is waveform movement of energy between different media.
Man uses energy from different sources, which can be set into two groups, namely, the renewable sources and the non-renewable sources. These renewable and non-renewable energy sources can be converted into secondary sources of energy such as electricity.
Energy can neither be created nor destroyed but it can be changed to different forms. For instance, solar energy can be converted to electrical energy in solar cells and light energy into heat energy in solar heating. Similarly, non-renewable energy from biomass can be converted to electrical energy.
Food is a stored form of energy and is stored in the chemical form with potential energy.
The food chain from the sun to humans explains the conversion of energy to different forms.
How is energy measured?
By definition energy is the ability to do work/or rate at which work is done. It can be measured as the work done:
Work = Force × Distance
Work as defined above is a measure of the force applied on a body to move it to some distance.
The energy/work required to move an object with the 1 newton of force over 1 meter distance is called a joule.
Energy is also expressed as calorie, which is the amount of heat required to raise temperature of 1 g of pure water (14.5 to 15.5°C at standard atmospheric pressure conditions).
1 calorie is equal to 4.1855 joules.
One kilocalorie or 1000 calories is equivalent to 4185 joules or 4.185 kJ.
British thermal unit (BTU) is another way of expressing energy. It is the amount of energy required to raise the temperature of one pound of water by 1°F.
Watt (W/m2 or Wm-2) is the metric unit of measurement of the intensity of radiation in watts over 1 square meter surface. One watt is equal to 1 joule of work per second. One kilowatt is as same as 1000 watts.
Electrical energy is measured as Amps, Volts, Watts, Kilowatts and Megawatts. Electrical energy consumption is usually given as Kilowatts hours. 1-kilowatt hour is equivalent to the consumption of one kilowatt of power for one hour.
Horsepower is another unit of measuring energy. 1 HP is equivalent to 745.7 watts.
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