1. (I) A child sitting 1.20 m from the center of a merry-go- round moves with a speed of 1.10 ms. Calculate (a) the centripetal acceleration of the child and (b) the net hori- zontal force exerted on the child (mass=22.5 kg).

1. (I) A jet plane traveling 1890 kmh (525 ms) pulls out of a dive by moving in an arc of radius 5.20 km. What is the plane's acceleration in g's?

1. (II) How fast (in rpm) must a centrifuge rotate if a particle 7.00 cm from the axis of rotation is to experience an accel- eration of 125,000 g's?