Some dragonflies splash down onto the surface of a lake to clean themselves. After this dunking, the dragonflies gain altitude, and then spin rapidly at about 1000 rpm to spray the water off their bodies. When the dragonflies do this "spin-dry," they tuck themselves into a "ball." If they spin with a linear speed of 2.3 m/s, and curl into a ball with a radius of 1.1 cm, what is the centripetal acceleration they produce?