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Energy
There are formulas for calculating a numerical quantity, we call energy. The joule J is its unity.
Explanation
In physics we have no knowledge of what energy is. It is a mathematical principle that has a large number of different forms:
• Chemical energy
• Elastic energy
• Electrical energy
• Gravitational energy
• Heat energy
• Internal energy
• Kinetic energy
• Mass energy
• Momentum energy
• Nuclear energy
• Photon energy
• Potential energy
• Quantum potential energy
• Radiant energy
• Relativistic energy
• Thermal energy
• Work energie
• Zero-point energy
When we observe a system in nature and calculate the quantity again, it always stays the same. The conservation of energy is one of the most basic laws of physics.
HistoryThe joule is named after the English physicist James Prescott Joule (1818 - 1889). |