Physics Circular Motion Level: Misc Level

A wheel has eight equally spaced spokes and a radius of 34 cm. It is mounted on a fixed axle and is spinning at 1.4 rev/s. You want to shoot a 21-cm-long arrow parallel to this axle and through the wheel without hitting any of the spokes. Assume that the arrow and the spokes are very thin. What minimum speed must the arrow have?