An open container holds 0.550 kg of ice at -15 Celsius. The mass of the container can be ignored. Heat is supplied to the container at the constant rate of 800 J/min for 500 min.(adsbygoogle = window.adsbygoogle || []).push({});

A) After how many minutes does the ice start to melt.

This part I calculated and got correct, it's 21.7 min.,

B) After how many minutes, from the time when the heating is first started, does the temperature begin to rise above 0 Celsius?

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This is where I'm stuck. What I did was say that Qtotal would be equal to Q1 (the heat necessary in part A) + Heat of Fusion of water * the mass of the ice.

so: Qt = Q1 + Lm

L is 335,000 J/kg

m is 0.550 kg

Q1 from part A is 17325 J.

So, Qt = 35750 J

Time is Qt/rate of transfer = 35750 / 800 = 44.7 min, but that's incorrect...

What am I messing up?

-Luis

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# Homework Help: Easy heat transfer problem stuck

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