Subtopic: Functional requirements, principles of working, construction and operation of manual, animal, tractor and renewable energy operated equipment for tillage, sowing, planting, fertilizer application, inter-cultivation, spraying, mowing, chaff cutting, harvesting and threshing
Question Statement:
A combine harvester rasp-bar threshing cylinder has an outer tip diameter of $D = 0.60\text{ m}$ and rotates at a speed of $N = 850\text{ rpm}$ while threshing wheat. The peripheral tip speed of the threshing cylinder in $\text{m/s}$ is ________ (round off to 2 decimal places).
Answer Key:
26.70
Step-by-Step Solution & Explanation
```
Rasp-Bar Threshing Cylinder:
Tip Diameter D = 0.60 m
Shaft Speed N = 850 rpm
v_c = pi * D * N / 60
```
**Step-by-step Calculation:**
1. Peripheral tip speed ($v_c$) of cylinder:
$v_c = \frac{\pi D N}{60}$
$D = 0.60\text{ m}, \quad N = 850\text{ rpm}$
$v_c = \frac{\pi \times 0.60 \times 850}{60} = \frac{510\pi}{60} = 8.5\pi = 26.7035\text{ m/s} \approx 26.70\text{ m/s}$
Standard peripheral speed for wheat threshing ranges between $25\text{--}30\text{ m/s}$.