Test Index

WAEC Physics 2017 Paper

Question : 16

Total: 50

\mathrm{J}\mathrm{g}^{-1}

]

Solution:

Concept:

Heat absorbed during melting is found using

Q = mL

, and it represents only 70% of the total heat supplied.

Explanation:

Mass of ice,

m = 50 \, \mathrm{g}

Specific latent heat of fusion of ice,

L = 336 \, \mathrm{J\,g^{-1}}

Heat required to melt the ice completely:

Q = mL = 50 \times 336 = 16800 \, \mathrm{J}

This

16800 \, \mathrm{J}

is 70% of the total heat energy supplied.

Let total heat supplied be

E

\frac{70}{100} \times E = 16800

E = \frac{16800 \times 100}{70} = 24000 \, \mathrm{J}

Answer:

Total heat energy supplied =

24000 \, \mathrm{J}

Correct option: D.

24000 \, \mathrm{J}

Go to Question:

Prev Question

Next Question