Apump, submerged at the bottom of a well that is 35 m deep, is used to pump water uphill to a house that is 50 m above the top of the well, as shown above. the density of water is 1,000 kg/m3. neglect the effects of friction, turbulence, and viscosity. (a) residents of the house use 0.35 m3 of water per day. the day’s pumping is completed in 2 hours during the day. i. calculate the minimum work required to pump the water used per day ii. calculate the minimum power rating of the pump. (b) in the well, the water flows at 0.50 m/s and the pipe has a diameter of 3.0 cm. at the house the diameter of the pipe is 1.25 cm. i. calculate the flow velocity at the house when a faucet in the house is open. ii. calculate the pressure at the well when the faucet in the house is open.

The amount of potential energy possessed by an elevated object is equal to

Lake happy times contains 100 km3 of pure water. it is fed by a river at a rate of 50 km3/yr. at time zero, there is a factory on one shore of lake happy times that begins introducing a pollutant to the lake at a rate of 2km3/yr. there is another river that is fed by lake happy times at a rate that keeps the volume of lake happy times constant. this means that the rate of flow from lake happy times into the outlet river is 52km3/yr. in turn, the flow from this outlet river goes into another lake, lake sad times, at an equal rate. finally, there is an outlet river from lake sad times flowing at a rate that keeps the volume of lake sad times at a constant 100 km3 . (a) find the amount of pollutant in lake sad times at the end of 3 months. (b) at the end of 3 months, observers close the factory due to environmental concerns and no further pollu- tant enters lake happy times. how long will it take for the pollutant in lake sad times (found in part (a)) to be cut in half?

The standard cell potential (e°cell) for the reaction below is +0.63 v. the cell potential for this reaction is when the concentration of zn2+ = 1.0 m and the concentration of pb2+ = 2.0 x 10-4 m. pb2+(aq) + zn(s) > zn2+(aq) + pb(s)