1.7. Find the specific surface area of coal used in mod

The seller is blocked and sales of the product are suspended

1.7. Find the specific surface area of coal used in modern pulverized fuel furnaces if it is known that coal dust is pre-sieved through a sieve with openings of 7.5 · 10–5 m. The density of coal is 1.8 · 103 kg / m3. Consider the system monodisperse. Give the answer in m – 1 and in m2 / kg.