SOLUTION: Water temp. coming into the house is 60 degrees f, some of the water goes into the hot water heater, which reaches 120 degrees f, you fill a bath tub with 22 gallons of water with

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Water temp. coming into the house is 60 degrees f, some of the water goes into the hot water heater, which reaches 120 degrees f, you fill a bath tub with 22 gallons of water with       Log On


   



Question 53522: Water temp. coming into the house is 60 degrees f, some of the water goes into the hot water heater, which reaches 120 degrees f, you fill a bath tub with 22 gallons of water with a temp. of 80 degrees f. What is the volume of cold water and the volume of hot water.
Answer by stanbon(75887) About Me  (Show Source):
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Water temp. coming into the house is 60 degrees f, some of the water goes into the hot water heater, which reaches 120 degrees f, you fill a bath tub with 22 gallons of water with a temp. of 80 degrees f. What is the volume of cold water and the volume of hot water
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There is alot of assuming here regarding thermodynamics but here goes.
Let the amount of heated water be "x" ; its heat content is 120x
The amount of unheated water is "22-x" ; its heat content is 60(22-x)=1320-60x
The amount of mixed water is 22 gallons ; its heat content is 80(22)=1760
EQUATION:
heat + heat = heat
120x + 1320-60x = 1760
60x == 440
x=7 1/3 gallons of hot water
22-x= 14 2/3 gallons of unheated water
Cheers,
Stan H.