Calculate δe, if q = 0.764 kj and w = - 830 j. express your answer using two significant figures.

Given:

Q = 0.0764 kJ = 764 J, heat input

W = - 830 J, useful work done

From the 1st Law of Thermodynamics, the change in internal energy is

δE = Q - W

= 764 - (-830)

= 1594 J = 1.594 kJ

Answer: 1.59 kJ (two sig. fig.)