2. A block with mass m = 4.00 kg is being pushed by an external force with magnitude F = 50.0 N, directed at an angle of 0 = 60.0 with respect to the horizontal as shown in the gure. The oor is frictionless between positions x = 0 and x = XE, and the block starts 0 D .".'.'.'.'c from rest at position x = 0. [1k a) If the block has a velocity of V1) = 5.00 m/s once it reaches position x = X1), then determine the displacement of the block D after it has traveled from position x = 0 to position x =X1). b) If the external force F no longer acts on the block once it reaches position x = X1), then determine the magnitude of the velocity of the block VE once it reaches position x = XE. The moment the block reaches position XE = 6.00 m, it comes into contact with a spring attached to a wall as shown in the gure. This spring has a spring constant of k = 20.0 N/m and is initially at equilibrium in its current position. Once the block reaches position Xc = 8.00 m, the spring has been fully compressed. However, unlike before, the oor is rough (i.e. friction exists) between the positions of x = XE and x =XC. c) Determine the coefcient of kinetic friction ,uk between the block and the oor in the region between the positions of x = XE and x = Xc. d) If the spring no longer acts on the block once it returns back to position x = XE, then determine the magnitude of the velocity of the block V'E once it reaches position x = XE for the second time