The body is then also submerged and the combined weight redetermined. The change in weight is due to the buoyant force of the water on the body and equal to the weight of the water displaced by the body. It therefore gives the volume of the body in cubic centimeters. The density is then determined as in the preceding case [8, http://ieeexplore.ieee.org/Xplore/ Browse/Journals/Education/IEEE_Transactions].
Read the text, translate it and answer the questions: For what purposes is lift pump used and what’s its construction? What’s the force pump principle of operation? What type of pump is called a single-acting pump and what is a double-acting one?