- #1
chawki
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Homework Statement
The density of water is 1000 kg/m3 and the specific heat capacity of water is 4.2Kj/(Kg.C)
Homework Equations
a) How much energy is required to heat 1.5 L of water at a temperature of 20 °C to the boiling point 100 ºC?
b) There is 1.5 L of water in a kettle on a cooking plate of 2.0 kW. It takes 7.0 minutes to
heat the water from a temperature of 20 ºC to the boiling point. How much electrical
energy is required? What is the efficiency of the heating process?
The Attempt at a Solution
a)
Q=m*Cp*T
Q=1.5*4.2*(100-20)
Q=504 Kj.
b)
how can we find the electrical energy?