Question: what is gj in physics?
Answer: ›› Definition: Gigajoule So 1 gigajoule = 109 joules. ... The joule (symbol J, also called newton meter, watt second, or coulomb volt) is the SI unit of energy and work. The unit is pronounced to rhyme with "tool", and is named in honor of the physicist James Prescott Joule (1818-1889).