WAEC - Physics (1996 - No. 18)
What is the difference in the amount of heat given out by 4kg of steam and 4kg of water when both are cooled from 100oC to 80oC? (Specific latent heat of steam = 2.260,000J kg-1) (Specific heat capacity of water =4,200 J kg-1)
336,000J
672,000J
8,704,000J
9,040,000J
9,376,000J
Explication
\(Q_{s} - Q_{w} = (4 \times 2260000) - (4 \times 4200 \times (100 - 80))\)
= \(9040000 - 336000\)
= \(8,704,000 J\)