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?

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

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~ :)

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

To calculate the number of joules taken in by a man who eats 4000 calories of food each day, you can convert the calories to joules using the conversion factor of 4.186 joules per calorie. You correctly calculated this as 16,744 joules (4000 x 4.186 = 16,744 joules).

The second question asks about the person's average thermal power output. Thermal power refers to the amount of energy transfer occurring per unit of time. In this case, it refers to the rate at which the man's body is converting the stored energy from food into heat energy.

To calculate the average thermal power output, you need to consider the time over which the energy is expended. Assuming the person consumes 4000 calories evenly throughout an entire day (24 hours), you can divide the energy intake in joules (16,744 joules) by the time in seconds.

To convert 24 hours to seconds, you can multiply by 60 (minutes per hour), then again by 60 (seconds per minute):
24 hours x 60 minutes/hour x 60 seconds/minute = 86,400 seconds

Finally, divide the energy intake (16,744 joules) by the time in seconds (86,400 seconds) to get the average thermal power output:
16,744 joules ÷ 86,400 seconds ≈ 0.194 joules/second or 194 millijoules/second

So, the person's average thermal power output can be estimated at approximately 0.194 joules per second (or 194 millijoules per second).