A block of copper of mass \(5 \mathrm{~kg}\) is heated to \(90^{\circ} \mathrm{C}\) and then plunged into an insulated container containing \(4 \mathrm{~L}\) of water at \(10^{\circ} \mathrm{C}\). Find the final temperature of the system. For copper, the specific heat is \(385 \mathrm{~J} / \mathrm{kg} \cdot \mathrm{K}\), and for water the specific heat is \(4186 \mathrm{~J} / \mathrm{kg} \cdot \mathrm{K}\).