The 50 kg block at A is mounted on rollers so that it moves along the fixed horizontal rail with negligible friction under the action of the constant 300 N force in the cable. The block is released from rest at A, with the spring to which it is attached extended an initial amount $x_{\text{1}}=0.\text{233m.}$  The spring constant is K= 80N/m. Calculate the velocity (in m/s) of the block as it reaches position B.