Answer is: 10460 kJ of energy is burned.
The large calorie or nutritional calorie (symbols: Cal, kcal) is the heat energy needed to raise the temperature of one kilogramof water by one degree Celsius.
A nutritional calorie, or kilocalorie, is equal to 1000 calories.
One large calorie is 4.184 kilojoules: 1 Cal = 4.184 kJ.
E = 2500 Cal; energy burnt.
E = 2500 Cal · 4.184 kJ/Cal,
E = 10460 kJ.
