If a person radiates about 74 W of power at room temperature, how long does it take for a person to radiate away the energy acquired by consuming a 235 Calorie doughnut?
http://scienceshareware.com/bicycle-generator-faq.htm#calories
A Calorie with a capital C is 1 kilocalorie. 1c=4.184 J, so 1kc=4,184 J. 235 C X 4,184 J = 983,240 J. 1 W is 1 J/second. Divide 983,240 J by 74 J/s, to get 13287.02703 seconds. Divide that by 3600 seconds/hour to convert to hours.
Answer in short: 13287.02703 s = 3.690840841 hours.
thank you! that was very helpful!
To answer this question, we need to make a few calculations. First, let's convert the power output to calories per second:
1 watt = 0.239006 calories/second
So, 74 watts = 74 * 0.239006 = 17.686444 calories/second
Next, we need to determine the energy content of the 235 Calorie doughnut:
1 Calorie = 1 kilocalorie = 4184 joules
So, 235 Calories = 235 * 4184 = 983140 joules
Now, we can calculate the time it takes to radiate away this energy:
Time = Energy / Power
Time = 983140 joules / 17.686444 calories/second
To convert joules to calories, we use the conversion factor:
1 calorie = 4.184 joules
Time = (983140 joules / 4.184 joules) / 17.686444 cal/sec
Time ≈ 1407.68 seconds
Therefore, it takes approximately 1407.68 seconds to radiate away the energy acquired by consuming a 235 Calorie doughnut at a power output of 74 watts.