Question

A tractor operated sprayer has 24 nozzles spaced 50 cm apart. Time lost in turning is 8% and filling the tank takes 7% of the time. If the sprayer is operated at a speed of 5 km/h, calculate the coverage area in ha per hour.

• A. 2.6
• B. 3.0
• C. 5.1
• D. 6.0

Hint:

First get the theoretical area covered per hour from swath width and speed, then reduce it by the total time lost.

Answer 1

The Correct Option is C

Set up the numbers directly. Working width \(W = 24 \times 0.5\ \text{m} = 12\ \text{m} = 0.012\ \text{km}\). Area covered per hour at full efficiency (no stoppage) is \(A = W \times v = 0.012\ \text{km} \times 5\ \text{km/h} = 0.06\ \text{km}^2/\text{h}\). Since 1 km\(^2\) = 100 ha, this equals \(0.06 \times 100 = 6\) ha/h, the theoretical capacity.

Now apply the losses. Turning eats 8% of the working time and tank filling eats another 7%, together 15% of the time is non-productive, leaving only 85% of the time actually spraying. So the real capacity is \(6 \times 0.85\).

\[6 \times 0.85 = 5.1 \text{ ha/h}\]\[\boxed{5.1\ \text{ha/h}}\]