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Thermodynamics weightlifter

  • Thread starter chukie
  • Start date
80
0
1. Homework Statement
A weight lifter manages to lift a 147 kg weight a distance of 1.1 m. Treat her as a thermodynamic system and find how much heat (in kcal) she must put out if her internal energy decreases by 3620 J during the lift.


2. Homework Equations

delta U=Q-W

3. The Attempt at a Solution

-3620= Q-(9.8*147*1.1)
Q=-2035.34

I was wondering wut the units of Q are? if it's in joules how do i convert to kcal?

Thanks in advance!:smile:
 

Answers and Replies

mgb_phys
Science Advisor
Homework Helper
7,744
11
Q is in Joules because you have used consistent metric units.
A kCal is approx 4184J - it's the energy need to heat 1cc of water 1deg C.
 

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