A coil is to be used as an immersion heater for boiling water. The coil is to operate at a voltage of 130 V and is to heat an amount of water with a volume of 251 cm^3 by 80.0 degree celsius in a time interval of 6.30 minutes.(adsbygoogle = window.adsbygoogle || []).push({});

Use 4190 J/(kg*K) for the specific heat capacity of water and 1000 kg/m^3 for the density of water.

The question is :

What must the resistance of the coil be (assumed temperature-independent)?

I have tried the following:

i solved for the m=DV=(1000kg/m^3)(2.51*10^-6m^3)=.251 kg

then i solved for Q=mcdeltaT

deltaT=80C+273=353K

Q=.251 kg(4190J/(kg*K))(353K)=371246.57J

then i divided it by 6.30 min

Q=(371246.57J/6.30min)*(1min/60s)=982.13J/s

R=V^2/P=(130^2)/(982.13)=17.207ohms

This sadly didn't work...please help me on this level 2 problem

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# Homework Help: E/m resistance problem

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