Food-energy to Mechanical Energy

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SUMMARY

The discussion centers on calculating the amount of butter required to convert food energy into mechanical energy for a mountaineer ascending from 2070m to 4196m. The nominal food-energy value of 1.00g of butter is approximately 7.20 food calories, equivalent to 30.1248 Joules. The user initially calculated the energy needed using the formula Mass * Gravity * Height, resulting in an incorrect butter mass of approximately 4.5x10^4g. The error was identified as a misunderstanding of food calories, which are actually kilocalories (Kcals), leading to the need for a recalibration of the calculations.

PREREQUISITES
  • Understanding of gravitational potential energy calculations
  • Familiarity with food energy conversions (calories to Joules)
  • Basic knowledge of mass and weight concepts
  • Proficiency in unit conversion, particularly between calories and kilocalories
NEXT STEPS
  • Study the conversion between food calories and Joules in detail
  • Learn about gravitational potential energy and its applications in physics
  • Explore the concept of energy efficiency in food-to-energy conversions
  • Investigate other food sources and their energy values for mechanical work
USEFUL FOR

Students in physics or nutrition, educators teaching energy conversion concepts, and anyone interested in the practical applications of food energy in physical activities.

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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