The correct answer is: C. 0.012
Porosity is the ratio of the volume of voids to the total volume of a material. It is a measure of how much empty space there is in a material. The porosity of sediments in sewer pipes is usually taken as 0.012. This means that for every 100 cubic centimeters of sediment, there are 1.2 cubic centimeters of voids.
The porosity of sediments in sewer pipes is important because it affects the flow of water through the pipes. The higher the porosity, the more water can flow through the pipes. This is important because it helps to prevent blockages and backups in the sewer system.
The porosity of sediments in sewer pipes can be affected by a number of factors, including the type of sediment, the grain size of the sediment, and the compaction of the sediment. The type of sediment refers to the material that makes up the sediment. The grain size refers to the size of the particles in the sediment. The compaction refers to how tightly packed the particles are in the sediment.
The type of sediment can affect the porosity of the sediment in a number of ways. For example, sand has a higher porosity than clay. This is because sand particles are larger than clay particles and they are not as tightly packed together.
The grain size of the sediment can also affect the porosity of the sediment. For example, coarse sand has a higher porosity than fine sand. This is because coarse sand particles are larger than fine sand particles and they are not as tightly packed together.
The compaction of the sediment can also affect the porosity of the sediment. For example, loose sediment has a higher porosity than compacted sediment. This is because loose sediment particles are not as tightly packed together as compacted sediment particles.
The porosity of sediments in sewer pipes is an important factor to consider when designing and maintaining sewer systems. The higher the porosity, the more water can flow through the pipes. This is important because it helps to prevent blockages and backups in the sewer system.