WAEC - Physics (2008 - No. 20)
Water of mass 1.5kg is heated from from 30oC to 80oC using an electric kettle which is rated 5A, 230V. Calculate the time taken to reach the final destination [specific heat capacity of water 4200Jkg-1K-1]
4.57 minutes
5.02 minutes
7.30 minutes
10.04 minutes
설명
t = \(\frac{MC\theta}{2} = \frac{1.5 \times 4200 \times 50}{5 \times 230}\)
= 273.91s or 4.57 mins
= 273.91s or 4.57 mins