For ice to melt, its temperature must be 0* C.
Q1 = heat required to raise the ice temp from -14.3* C. to 0* C.
Q2 = heat required to melt the ice
Q1 = MCp(delta T)
Q2 = m(Hf)
M = mass of the ice = 0.6 kg (given)
Cp = specific heat of ice = 2100 J/kg K (given)
delta T = temperature change = 0 - -14.3 = 14.3* C.
Hf = heat of fusion of ice = 334 x 10^3 J/jg.
Q1 = 0.6(2100)(14.3)
Q1 = 18018 joules
Q2 = 0.6(334 x 10^3)
Q2 = 200400 joules
Total heat required to melt the ice = Q1 + Q2 = 218418 joules
<< How much time T_melt passes before the ice starts to melt? >>
Tmelt = Q1/890 = 18018/890 = 120.24 minutes
<< From the time when the heating begins, how much time T_rise does it take before the temperature begins to rise above 0*C? >>
Trise = (Q1 + Q2)/740
Trise = 218418/890 = 245.41 minutes