WAEC - Physics (1994 - No. 40)
Calculate the time taken to heat 2kg of water from 50°C to 100°C in an electric kettle taking 5A, from a 210V supply. (Specific heat capacity of water = 4200\(kg^{-1}K{-1}\)
2.5 minutes
5.7 minutes
6.7 minutes
7.5 minutes
9.5 minutes
Explanation
t = \(\frac{mc\theta}{p}= \frac{2\times4200\times50}{210\times5} \\ = 400s = 6.7\)
Comments (0)
