WAEC - Physics (2006 - No. 22)
How long will it take to heat 3kg of water from 28oC to 88oC in an electric kettle taking 6a from a 220V supply? [specific heat capacity of water = 4180 J kg-1K-1]
120s
570s
600s
836s
Explicació
t = \(\frac{mc\theta}{IV} = \frac{3 \times 4189 \times 60}{6 \times 120} = 570s\)