The average adult human burns 2.00 * 10 ^ 3 kcal per day in energy. What is this rate in kJ per hour

Answer 1

To answer problems of this nature, it requires one to know (or look up) certain conversion factors. Just as you know that there are 12 inches in 1 foot, and 3 feet in 1 yard, there are also 4.184 kJ in 1 kcal. So, using this conversion factor, we can now use dimensional analysis to answer this question.

2.00x10³ kcal x 4.184 kJ/kcal = 8.368x10³ kJ = 8.37x10³ kJ

(note how kcal cancel leaving you with kJ)