A child weighing around 40 kg stands on the rim of an idle carousel that has a diameter of 10 m and a moment of inertia of 2000 kg·m². Note that the carousel can rotate without any significant friction. When she starts running along its circumference at a speed of 3.0 m/s, the carousel will begin to move in reverse direction. What will be its angular velocity in this case? Please treat the angular velocity of the child with respect to the ground to be positive and think of the carousel as a solid cylinder.