Question

What is the change in the internal energy of a system in which 66.1 kJ of heat is transferred to the surroundings while the surroundings do 44.0 kJ of work on the system? Provide an answer that is correct to 3 significant figures. 

Answer 1

$\Delta\>u=Q-w$

$Q=+66.1kJ$

$w=(-44.0kJ)$

$\implies\Delta\>u=66.1-(-44.0)$

$=110.1$

$=110kJ($ 3 significant figures$)$