How many joules are taken in by a man who eats 4000 calories of food each day? What is this person's average thermal power output?

Question

4000 x 4.186 =16 744Joules, but I don't understend second question, Thank you for helping me.

Answer 1

the conversion factor for calories (cal) and joules (J) is:
1 cal = 4.184 J
now to convert calories to joules, we multiply 4000 cal by 4.184 J / 1 cal so that the cal unit will be canceled, and the numerator will have the unit J:
4000 cal * 4.184 J / cal = 16736 J

hope this helps~ :)

Answer 2

A person uses 730 to run a race. Convert the energy used for the race to the following energy units. joules kilojoules