# SOLUTION: There is 1.5 L of water in a kettle on a cooking plate of 2.0 KW. It takes 7 minutes to heat the water from 20 C to the poiling point. a) How much electrical energy is required ?

Algebra ->  Test  -> Lessons -> SOLUTION: There is 1.5 L of water in a kettle on a cooking plate of 2.0 KW. It takes 7 minutes to heat the water from 20 C to the poiling point. a) How much electrical energy is required ?       Log On

 Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations! Ad: Mathway solves algebra homework problems with step-by-step help!

 Test Calculators and Practice Answers archive Word Problems Lessons In Depth

 Question 388758: There is 1.5 L of water in a kettle on a cooking plate of 2.0 KW. It takes 7 minutes to heat the water from 20 C to the poiling point. a) How much electrical energy is required ? b) What is the efficiency of the heating processAnswer by Jk22(389)   (Show Source): You can put this solution on YOUR website!a) 14/60 kWh = 0.84 MJ b) the heat capacity of water is 4180 J/kg/K, hence 1.5 l that is heated by 80 degrees needs an energy of : 4180*1.5*80 = 0.5016 MJ hence the efficiency of the process is : (0.84 - 0.5016)/0.5016 = 67 %