<Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (August 2015) (Learn how and when to remove this template message) </Td> </Tr> <P> Because energy is defined via work, the SI unit for 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 </P> <Dl> <Dd> 1 J = 1 k g (m s) 2 = 1 k g ⋅ m 2 s 2 (\ 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)))) </Dd> </Dl> <Dd> 1 J = 1 k g (m s) 2 = 1 k g ⋅ m 2 s 2 (\ 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)))) </Dd>

Which one of the following is the unit of energy