specific heat capacity of water C = 4186 J/kg/oC
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capacity of water in heater = 49.1 gallons
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= 49.1 x 3.785 = 185.84 litre
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185 .84 litre of water = 185.84 kg
Heat required to raise the temperature from 18.8oC to
62.1oC
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H = 4186 x ( 62.1 - 18.8 ) x 185.84
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H = 33684206.19 J
power of heater P = 4610
WÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
1 W = 1 J/s
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t = 33684206.19 / 4610
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t =7306.8 s
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t = 7306.8 / 60 x 60
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t = 121.7 min = 2 hr 2 min
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t = 2hr 2 min