Question

The heat of fusion of iron is 209 Joules/gram. Between two amounts of iron 50 grams and 100 grams, which of the two will take a longer time to melt completely?

A. 100 g of iron

B. They will melt at the same time

C. Cannot be determine

D. 50 g of iron

Answer 1

$$Q=mL=hA\Delta T t=hA\frac{m}{\rho R}\Delta T t$$

$$Rt=const$$

Thus, 100 grams will take a longer time to melt completely.

Answer: A. 100 g of iron