The 210-kg crate rests on the ground for which the coefficients of static and kinetic friction are u, 0.5 and u = 0.4, respectively. The winch delivers a honzontal towing force T to its cable at A which varies as shown in the graph. Originally the tension in the cable is zero. (Figure 1) Figure 1 of 1> T(N) 800 T= 400 2 t(s) AT Part A Determine the speed of the crate when t = 3.9 s Hint First determine the force needed to begin moving the crate Express your answer to three significant figures and include the appropriate units. Value Units Submit RequestAnswer