Allied & ICAR Exam Bank • ALLIED_1058NAT • 2 Marks
Section 2: Farm Machinery
Farm Machinery
Subtopic: Harvesting and Threshing Equipment
Question Statement:
In a reciprocating mower, the crank speed is 900 rpm. If the stroke length is 76.2 mm, the average linear cutting speed of the knife in m/s is:
Answer Key:
2.29
Step-by-Step Solution & Explanation
In one revolution, the knife travels two strokes: distance $= 2S = 2 \times 0.0762\text{ m} = 0.1524\text{ m}$. At 900 rpm ($15\text{ rev/s}$), average speed $v_{avg} = 2 S \times N = 0.1524 \times 15 = 2.286\text{ m/s}$.