A bucket wheel excavator with 20 buckets of capacity 0.5 m<sup>3</sup> each, rotates at 5 rev/min. The bucket fill factor is 80%. The excavator loads on to 1200 mm wide belt conveyor. The cross-section area (m<sup>2</sup>) of the material on the belt is 0.1B<sup>2</sup>, where B is the belt width in m. The minimum speed of the belt in m/s to avoid spillage of material is

Correct Answer: 4.63