There are two forces on the 2.69 kg box in the overhead view of the figure but only one is shown. For F1 = 22.9 N, a = 10.3 m/s, and 0 = 25.4, find the second force (a) in unit-vector notation and as (b) a magnitude and (c) a direction. (State the direction as a negative angle measured from the +x direction.) y F 15 x