Food-energy to Mechanical Energy

AI Thread Summary
The discussion revolves around calculating the amount of butter needed to convert food energy into mechanical energy for a mountaineer ascending from 2070m to 4196m. The initial calculation used the formula for gravitational potential energy, resulting in an estimate of approximately 45,000 grams of butter. However, the error was identified in the conversion of food calories, clarifying that food calories are actually kilocalories, equating to 1 kilocalorie being 1000 calories. This correction significantly impacts the total energy calculation and the required amount of butter. The discussion concludes with an acknowledgment of the importance of accurate unit conversion in energy calculations.
raiderIV
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Homework Statement


The nominal food-energy value of 1.00g of butter is about 7.20 food calories.

If all this energy could be converted completely to mechanical energy, how much butter would be required to power a 65.0kg mountaineer on her journey from Lupine Meadows (elevation 2070m) to the summit of Grand Teton (4196m)?


Homework Equations


Mass*Gravity*Height


The Attempt at a Solution



What I tried was (65 * 9.81 * 2126) to find the Joules of energy required for the journey. Then converted 7.2 food calories to 30.1248J and divided to find the grams.

I came out with approx 4.5x10^4g of butter, however it is not being accepted as correct.
What am i doing wrong?
 
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Note that food calories are really Kcals = 1000 calories.
 
Yep that solved it...

Thank you for the correction!
 

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