Powering the Human Brain: How Long Can One Snickers Bar Last?

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tennischick89
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1. The human brain consumes about 22 W of power under normal conditions, though more power may be required during exams. How long can one Snickers bar (280 cal per bar) power the normally functioning brain? [Note: The nutritional calorie, 1 cal, is equivalent to 1000 calories (1000 cal) as defined in physics. In addition, the conversion factor between calories and joules is as follows: 1 cal = 1000 calories = 1 kcal = 4186 J]


2. I know I need to use P=W/t



3. I converted cal. in the snickers bar to kcal and then did .280 kcal/4186 to get joules in one snickers. plugged that in for W but I'm not getting the right answer
 
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hi tennischick89! welcome to pf! :wink:
tennischick89 said:
1 cal = 1000 calories = 1 kcal = 4186 J]
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3. I converted cal. in the snickers bar to kcal and then did .280 kcal/4186 to get joules in one snickers. plugged that in for W but I'm not getting the right answer

you divided by 4186?

eat more snickers bars! :smile:​