A three$-$entry development section is driven $2,500$ feet; it has one intake $(K=60E-10lb-mi\frac{n^2}{f}t),$

one exhaust $(K=80E-10lb-mi\frac{n^2}{f}t),$ and one belt haulage way $(K=90E-10lb-mi\frac{n^2}{f}t)$ as the

entry layout design. The coal seam is $5-$feet thick, and the drives are $18-$feet wide. Determine the

air horsepower required to move $46,732cfm$ of ventilation air through the system. $(10$ Points$)$