The 0.4-lb ball and its supporting cord are revolving about the vertical axis on the fixed smooth conical surface with an angular velocity of 4 rad /sec. the ball is held in the position b = 14 in. by the tension t in the cord. if the distance b is reduced to the constant value of 9 in. by increasing the tension t in the cord, compute the new angular velocity and the work w1-2 done on the system by t