SOLUTION: A hot bar of iron at 1100 degrees Fahrenheit is quenched in oil at 350 degrees. After 2 minutes, the temperature of the iron is 750 degrees.
(a) Find the value for k in Newton's
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-> SOLUTION: A hot bar of iron at 1100 degrees Fahrenheit is quenched in oil at 350 degrees. After 2 minutes, the temperature of the iron is 750 degrees.
(a) Find the value for k in Newton's
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Question 1176052: A hot bar of iron at 1100 degrees Fahrenheit is quenched in oil at 350 degrees. After 2 minutes, the temperature of the iron is 750 degrees.
(a) Find the value for k in Newton's Law of Cooling. Round your answer to the nearest thousandth.
k= ?
(b) What will the temperature of the iron be after 10 minutes? Round your answer to the nearest degree.
? degrees Fahrenheit
(c) How long will it take for the iron to reach 400 degrees? Round your answer to the nearest tenth of a minute.
? minutes Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! T(t)=Ts+(To-Ts)*e^(-kt)
at 2 minutes
750=350+(1100-350)*e^(-k*2)
400=750*e^(-2k)
(8/15)=e^(-2k)
ln both sides
-0.6286=-2k
k=0.3143
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at 10 minutes e^(-kt)=e^(-3.143)=0.04315
(750)*0.04315 = 32.36 degrees, so the temperature will be 382 degrees F.
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at 400 degrees
400=350+(750*e^(-0.3143t)
(1/15)=e^(-0.3143t)
ln both sides
-2.708=-0.3143t
t=8.6 minutes.
