1) In 2011, the total of all residential customers in Halton Region used 54 540 000 m3 of water. Halton Region has a population of around 500 000 people and Milton (part of Halton Region) has a population of around 85 000 people. Assuming all people in Halton use the same amount of water, how much water was used in Milton in 2011?
V = 5.454e7m^3 ( 85000) = 9 271 800 m^3
2) 1 cm3 = 1 mL. The density of water is 1 g/cm3. Approximately what mass of water did Milton use in 2011?
mass = ρ(V) = 1000kg/m^3 ( 9.2718e6m^3) = 9.27e9 kg
3) Most houses in Milton draw their water from the municipal system that draws its water from Lake Ontario. Lake Ontario is 74 m above sea level and Milton is 221 m above sea level. The majority of the water in Milton passes through the water tower on Steeles Ave. It is 55 m from ground to top. In total, how much vertical distance must the water rise from Lake Ontario to the water tower?
202
4) How much gravitational potential energy does each kg of water gain travelling from Lake Ontario to the top of the water tower?
5) How much energy was needed to bring all the water used in Milton in 2011 from Lake Ontario to the water tower?
6) The energy used to lift the water comes from an electric water pump. Assuming the pump is 85% efficient at lifting the water, how much input electrical energy is needed for a year to lift the water?
7) Much of the energy used by the pump comes from natural gas fired plants (like the new one on Steeles Ave.). A typical efficiency for these power plants is 50%.
a. How much input energy (in the form of chemical energy) from natural gas is needed for a year to lift the water?
b. The chemical energy released from natural gas is around 35 MJ (Mega-Joules) per m3. What volume of gas needs to be burned to pump a year’s worth of water to Milton?
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