Farm Machinery

A combine harvester threshing cylinder has diameter $D = 0.6\text{ m}$ (radius $r = 0.3\text{ m}$). To maintain recommended peripheral speed $v = 30.0\text{ m/s}$ for wheat threshing, cylinder rotational speed $N = \frac{60 v}{\pi D} = \frac{60 \times 30.0}{3.1416 \times 0.6}$ in rpm is (rounded off to nearest integer):