First Law of Thermodynamics Video Lessons

Concept

# Problem: A system has a heat source supplying heat to an ideal gas at a rate of 187.0 W and the gas is doing work at a rate of 130.9 W. At what rate is the internal (thermal) energy of the gas changing?(a) 56.1 W(b) 318 W(c) 187 W(d) -56.1 W

###### FREE Expert Solution

From the first law of thermodynamics:

$\overline{){\mathbf{U}}{\mathbf{=}}{\mathbf{Q}}{\mathbf{-}}{\mathbf{W}}}$

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###### Problem Details

A system has a heat source supplying heat to an ideal gas at a rate of 187.0 W and the gas is doing work at a rate of 130.9 W. At what rate is the internal (thermal) energy of the gas changing?
(a) 56.1 W
(b) 318 W
(c) 187 W
(d) -56.1 W