$($Elliott P$2\mathrm{.}10)$ A block of copper weighing $0\mathrm{.}2kg$ with an initial temperature

of $400K$ is dropped into $4kg$ of water initially at $300K$ contained in a perfectly

insulated tank. The tank is also made of copper and weighs $0\mathrm{.}5kg.$ Solve for

the change in internal energy of both the water and the block given $Cv=4\mathrm{.}184$

$\frac{J}{g}-K$ for water and $0\mathrm{.}380\frac{J}{g}-K$ for copper. $($ANS$.7480J,-7570J)$