Average power consumption in watts

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Homework Help Overview

The discussion revolves around calculating average power consumption in watts based on a daily caloric intake and comparing it to gravitational energy changes associated with climbing Mount Everest. The subject area includes concepts of energy conversion, power, and gravitational potential energy.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss converting food calories to joules and the definition of a watt. Questions arise regarding the calculation of work and potential energy associated with climbing a height.

Discussion Status

Some participants have made attempts to calculate the average power consumption and the equivalent days of caloric intake for the energy required to ascend Mount Everest. There is acknowledgment of a typo in the energy conversion factor, indicating an ongoing clarification process.

Contextual Notes

Participants note the inefficiency of the body in converting chemical energy to gravitational energy and the need for additional information regarding the work done in the calculations.

enchanteuse
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Homework Statement



(a) If you follow a diet of 2140 food calories per day (2140 kilocalories), what is your average power consumption in watts? (A food or "large" calorie is a unit of energy equal to 4.2*10^3 J; a regular or "small" calorie is equal to 4.2 J.) Note for comparison that the power consumption in a table lamp is typically about 100 watts.
___ watts
(b) How many days of a diet of 2140 large calories are equivalent to the gravitational energy change from sea level to the top of Mount Everest, 8848 m above sea level? Assume your weight is 61 kg. (The body is not anywhere near 100% efficient in converting chemical energy into change in altitude. Also note that this is in addition to your basal metabolism.)
____ days

Homework Equations



Power = F * v
Power = W / delta t

I know that 1 watt = 1 J/s

The Attempt at a Solution



I converted 2140 calories to Joules, which is 2140 * (4.2*10^3) = 8988000 J
I'm not sure what I need to do from there because I can't figure out the work.

Any help would be appreciated!
 
Physics news on Phys.org
What is the definition of a watt?

If you have Joules in a day, and you can figure out how many seconds are in a day ...

As to Everest what is the potential energy increase required? m*g*h ?
 
I figured it out:)

a) (2140 cals *2400 J) / (24 days * 60 minutes * 60 seconds)

b) (61 kg * 8848 m * 9.8 m/s) / (2140 cals *2400 J)
 
enchanteuse said:
I figured it out:)

a) (2140 cals *2400 J) / (24 days * 60 minutes * 60 seconds)

b) (61 kg * 8848 m * 9.8 m/s) / (2140 cals *2400 J)

Weren't you using 4.2*10^3 J ?
 
Good catch! That was a typo...I meant 4.2 * 10^3 J.

Thanks LowlyPion:)
 

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