A 5cm thick ice block is there on the surface of water in a lake. The temperature of air is −10∘ C; how much time it will take to double the thickness of the block
(L=80 cal/g,Kice=0.004 Erg/s−k,dice=0.92gcm−3)
t=QlKA(θ1−θ2)=mLlKA(θ1−θ2)=VρLlKA(θ1−θ2)
=5×A×0.92×80×5+1020.004×A×10×3600=19. 1 hours.