SOLUTION: The heat H developed in an electric resistor varies jointly as the time t and the square of the current i in the resistor. If H^0 joules of heat are developed in t^0 seconds with i

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: The heat H developed in an electric resistor varies jointly as the time t and the square of the current i in the resistor. If H^0 joules of heat are developed in t^0 seconds with i      Log On


   

Question 436180: The heat H developed in an electric resistor varies jointly as the time t and the square of the current i in the resistor. If H^0 joules of heat are developed in t^0 seconds with i^0 amperes passing through the resistor:
i) Set up the proportionality relationship.
ii) How much heat is developed if both the time and the current are tripled?
Answer by stanbon(75887) About Me  (Show Source):
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The heat H developed in an electric resistor varies jointly as the time t and the square of the current i in the resistor. If H^0 joules of heat are developed in t^0 seconds with i^0 amperes passing through the resistor:
i) Set up the proportionality relationship.
Ho = k*to*io^2
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ii) How much heat is developed if both the time and the current are tripled?
Heat = k(3to)(3io)^2
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Heat = k(3to)(9io)
Heat = 27k*to*io
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The heat is multiplied by 27.
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Cheers,
Stan H.
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