IQF $($Individually Quick Freezing$)$ system is a system that allows each grain and particle to freeze separately and quickly by passing cold air over the food items. In the IQF system, strawberries with a diameter of $2\mathrm{.}8$ cm are frozen by cold air at $-40$deg C with a speed of $13$ m$/$s$.$ Strawberries enter the IQF system at $25$deg C$.$ In this system, calculate the time required for the center point of the strawberries to freeze by using the "Single Term Approximation" method. Strawberries will be considered spheres. $($Strawberry$-$related properties: Freezing point $-1\mathrm{.}8$deg C$,$ density $1050$ kg$/$m$3,$ thermal conductivity coefficient $0\mathrm{.}545$ W$/$m K$,$ Thermal diffusivity $0\mathrm{.}13$x$10-6$ m$2/$s$,$ specific $1$s$13\mathrm{.}99$ kJ$/$kg K$)$