sixty - three joules of heat are added to a closed system. the initial internal energy of the system is 58…

Explanation:

Step1: Recall the first - law of thermodynamics

$\Delta U=Q - W$, where $\Delta U$ is the change in internal energy, $Q$ is the heat added to the system, and $W$ is the work done by the system.

Step2: Calculate the change in internal energy

$\Delta U=U_{f}-U_{i}$, with $U_{i} = 58\ J$ and $U_{f}=93\ J$. So, $\Delta U=93 - 58=35\ J$.

Step3: Rearrange the first - law formula to solve for work

From $\Delta U=Q - W$, we can get $W = Q-\Delta U$. Given $Q = 63\ J$ and $\Delta U = 35\ J$. Then $W=63 - 35 = 28\ J$.

Answer:

A. 28 J