What gauge pressure in the water mains is necessary if a fire-hose is to spray water toa height of 15 m?
Diane B. ** although the one sold at some craft stores called Studio By Sculpey Glaze is probably the same thing as that gloss Varathane but rebottled under the Polyform brand, and more expensive of course. Note that it's not the same as the Sculpey Glaze though, which is not as good as Varathane.
i believe that Einstein's explanation of gravity as being like a rubber sheet universe. this description is pretty good. (it's from YA in the UK !) The rubber sheet is an imperfect analogy. It is intended to help us visual a 3D slice of 4D space-time. The vertical dimension of the rubber sheet represents gravitational potential; the vertical slope at any point on the sheet represents gravitational field strength. The closer your are to the sun, the greater the field strength. Object fall at a rate which is proportional to the field strength. Planets closer to the sun fall toward the sun faster; their faster orbital speed keeps them from falling into the sun. there ought to be a video showing a rubber sheet universe on the net somewhere, but i can't find one. However, if you Google rubber sheet universe images you will see some good still examples of how gravity seems to work. It isn't a perfect model, but it is pretty good.
They will replace it. I have seen companies come in and repair large lines in industrial settings. They first insert a new plastic liner and then inflate it. I didn't learn or I have forgot how they cured it, I think it was heat though. Then they cut the ends of the plastic balloon off and the line was repaired. Residential lines aren't that big, and besides if it's bad in one spot there have to be others that are close to failing too. Good luck
