A tabletop micro-centrifuge spins at 6000 rpm (revolutions per minute). When the lid is opened, the automatic shut-off circuit kicks in and the micro-centrifuge begins to slow down with a constant angular deceleration. In the first 10.0 seconds immediately after the shut-off, it the micro-centrifuge completes 654 full revolutions. Calculate the angular acceleration rate of the slowing micro-centrifuge in units of rad/s2. (Report your answer as a negative number to reflect the fact that the device is actually decelerating)