A force platform is a tool used to analyze the performance of athletes measuring the vertical force that the athlete exerts on the ground as a function of time. Starting from rest, a $\backslash (68\mathrm{.}0-\backslash$mathrm$\{$kg$\}\backslash )$ athlete jumps down onto the platform from a height of $0\mathrm{.}690$ m $.$ While she is in contact with the platform during the time interval $\backslash (0$