D. Define
15. Unit of energy
Answers
Answer:
joule is the unit of energy.
Answer:
As energy is defined via work, the SI unit of energy is the same as the unit of work – the joule (J), named in honor of James Prescott Joule and his experiments on the mechanical equivalent of heat. In slightly more fundamental terms, 1 joule is equal to 1 newton metre and, in terms of SI base units
{\displaystyle 1\ \mathrm {J} =1\ \mathrm {kg} \left({\frac {\mathrm {m} }{\mathrm {s} }}\right)^{2}=1\ {\frac {\mathrm {kg} \cdot \mathrm {m} ^{2}}{\mathrm {s} ^{2}}}} 1\ {\mathrm {J}}=1\ {\mathrm {kg}}\left({\frac {{\mathrm {m}}}{{\mathrm {s}}}}\right)^{2}=1\ {\frac {{\mathrm {kg}}\cdot {\mathrm {m}}^{2}}{{\mathrm {s}}^{2}}}
An energy unit that is used in atomic physics, particle physics and high energy physics is the electronvolt (eV). One eV is equivalent to 1.60217653×10−19 J.
In spectroscopy the unit cm−1 ≈ 0.0001239842 eV is used to represent energy since energy is inversely proportional to wavelength from the equation {\displaystyle E=h\nu =hc/\lambda } E=h\nu =hc/\lambda .
In discussions of energy production and consumption, the units barrel of oil equivalent and ton of oil equivalent are often used. Cubic mile of oil is sometimes used as a unit of energy in discussions of global scale energy