In a thermodynamic process, pressure of a fixed mass of a gas is changed in such a manner that the gas release `20 J` of heat and `8 J` of work is done on the gas. If initial internal energy of the gas was `30 J`, what will be the final internal energy?

Answer

`18J`

Explanation

`dU = dQ - dW, U_(2) - U_(1) =- 20 +8 =- 12`
`U_(2) = 30 - 12 = 18J`