Tractor 18

A tractor pulls four seeders, each 18/5 meters wide. The tractor moves at a speed of 4.5 km/h during sowing. How many hectares of field will the tractor driver sow in 7.5 hours?

Correct answer:

S =  48.6 ha

Step-by-step explanation:

$$\begin{gathered} n=4 \\ a=\frac{18}{5}=3.6\text{m} \\ v=4.5\text{km/h}\to \text{m/s}=4.5:3.6\text{m/s}=1.25\text{m/s} \\ t=7.5\text{h}\to \text{s}=7.5\cdot 3600\text{s}=27000\text{s} \\ s=v\cdot t=1.25\cdot 27000=33750\text{m} \\ b=n\cdot a=4\cdot 3.6=\frac{72}{5}=14.4\text{m} \\ {S}_1=b\cdot s=14.4\cdot 33750=486000{\text{m}}^2 \\ S=S_1\to \text{ha}=S_1:10000\text{ha}=486000:10000\text{ha}=48.6\text{ha}=48.6\text{ha} \end{gathered}$$

Try another example