Question

A 140-lb person burns about 2500 Calories to run a marathon. Part A How much energy is burned in kJ? Assume two significant figures.

Answer 1

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.