One end of a horizontal spring with force constant 130 n/m is attatched to a vertical wall. a 3 kg block sitting on the floor is placed against the spring. the coefficiton of kinetic friction between the block and the floor is 0.4. you apply a constant force to the block. f has magnitude 81 n and is directed toward the wall. the spring is compressed 80 c. what is the sped of the block?