Subjects/Basic Physics/Thermodynamics/First law of thermodynamics15. ThermodynamicsFirst law of thermodynamicsIn 15. ThermodynamicsFormulaCopy LaTeXΔU=Q−WDetailConvention: Q>0 enters the system and W>0 is work done by the system.Related formulasRelatedInternal energy of a monatomic ideal gasU=23nRTOpen formulaOpen in sectionRelatedThermodynamic workW=∫ViVfPdVOpen formulaOpen in sectionRelatedIsothermal process of an ideal gasPV=constanteOpen formulaOpen in section