Objects A and B have the same mass of 4.3 kg and are at their melting points. They melt when 4.9 × 104 J of heat is added to A and when 12 × 104 J is added to B. (a), (b) Determine the latent heat of fusion for the substance from which each object is made. (c) Find the heat required to melt object A when its mass is 8.6 kg.

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cici · Accepted Answer

(A) melting point of a = 4.9*10^4 J mass of a = 4.3 kg
melting point of a / mass of a = 11395.35 J/kg

(B) melting point of b = 12*10^4 J mass of b = 4.3 kg
melting point of b / mass of b = 27906.97 J/kg [WileyPlus answer would also be 2.8E4 J/kg]

(C) latent heat of fusion from A * mass of A
(11395.35 J/kg) * 8.6 kg = 98000.01 J

scott · Answer

latent heat of fusion is the heat required to melt a substance

the heat absorbed by a substance at it's melting point
... no temperature change ... a phase change from solid to liquid

usually given in ... Joules per gram ... heat / mass

for (c) ... more mass needs more heat to melt ... direct proportion