Answer
(a) $1.6\times10^{4}J$
(b) $-4.2\times10^{4}J$
(c) $-2.6\times10^{4}J$
Work Step by Step
(a) The work (W) = $1.6\times10^{4}J$
(b) The change in internal energy $(\Delta U)=-4.2\times10^{4}J$
(c) Let's apply the first law of thermodynamics,
$$Q=\Delta U+W$$
Let's plug known values into this equation.
$Q=-4.2\times10^{4}J+1.6\times10^{4}J=-2.6\times10^{4}J$