Neco Model Questions Vol1 2022 Agricultural Science Question 4

A farmer uses a 25 kW diesel tractor to plough a field. The tractor's fuel tank capacity is 60 L. During a field test the tractor ploughs a 2.5 ha field in 4 hours, consuming 45 L of diesel. The diesel has an energy content of 38.6 MJ per litre. The farmer also records the average soil resistance encountered as 12 kN and the average travelling speed of the tractor as 2.0 km/h. Using this information the farmer wants to: a) determine the average power delivered to the soil (in kW) from the measured force and speed; b) calculate the overall mechanical efficiency of the tractor (ratio of power delivered to soil to the rated engine power); c) estimate the specific fuel consumption (SFC) in litres per kilowatt‑hour for the tractor based on the field test; d) discuss two practical measures that could be taken to improve the tractor's fuel efficiency in field operations.