posted by student
1. a large vertical rectangular plate of glass is to be inserted in the wall of an aquarium underwater so visitors can see into the tank fo fish. the glass is 10 feet high, 25 feet long and the top fo the glass is 3 feet below the top of the water. The pressure exerted by water at depth b feet below the surface is .433b pounds/square inch. Your task is to set up the integral to compute the total pressure of the water (in pounds)against the glass.
2. What fraction of the pressure if exerted against the bottom half of the glass?
Once again, whoever wrote this question does not seem to know the difference begtween force and pressure, and probably should not be teaching the subject.
I already answered part 1, in a separate post. For the second question, compare the average depth of the top half of the glass (3 + 2.5 = 5.5 feet) to the average depth of the bottom half (3 + 7.5 = 10.5 feet). The fraction of the total FORCE exterted on the bottom half is 10.5/(10.5 + 5.5) = 10.5/16 = 21/32.