Ice at is added to 50 g of water at

PHYSICS · Single correct · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics

Problem

Ice at

-20^\circ\text{C}

is added to 50 g of water at

40^\circ\text{C}

. When the temperature of the mixture reaches

0^\circ\text{C}

, it is found that 20 g of ice is still unmelted. The amount of ice added to the water was close to (Specific heat of water =

4.2 \text{ J/g}^\circ\text{C}

Specific heat of Ice =

2.1 \text{ J/g}^\circ\text{C}

Heat of fusion of water at

0^\circ\text{C} = 334 \text{ J/g}

) (1) 50g (2) 100 g (3) 60 g (4) 40 g