Refer to the temperature versus time graph $($Figure $2)$ when answering the questions in Parts C through F$.$ A system consists of $0\mathrm{.}250$ kgkg of water. The system, originally at TA$=21\mathrm{.}0$C$,$ is placed in a freezer, where energy is removed from it in the form of heat at a constant rate. The figure shows how the temperature of the system takes t$1=10$min$=600$s to drop to $0$C$,$ after which the water freezes. Once the freezing is complete, the temperature of the resulting ice continues to drop, reaching temperature TB after an hour. The following specific heat and heat of transformation$$values for water may be helpful.

specific heat of ice $($at $0$C$)$ci $=2100$ J$/($kg$$K$)$ heat of fusion $($ice to water phase change at $0$C$)$ Lf $=3\mathrm{.}34105$ J$/$kg specific heat of water $($at $15$C$)$ cw $=4186$ J$/($kg$$K$)$ heat of vaporization $($water to steam phase change at $100$C$)$ Lv $=2\mathrm{.}26106$ J$/$kg specific heat of steam $($at $110$C$)$ cs $=2010$ J$/($kg$$K$)$

At what time t$2$ will the water be completely frozen so the temperature can begin to fall below $0$C$?$

Express your answer numerically in seconds.