Peoples Physics Concepts

http://www.ck12.org Chapter 18. Thermodynamics and Heat Engines

e. While keeping the sample at constant temperature, enough gas is allowed to escape to decrease the

pressure by half. How many gas atoms are there now?

f. Is this number half the number from part (a)? Why or why not?

g. The closed container is now compressed isothermally so that the pressure rises to its original pressure.

What is the new volume of the container?

h. Sketch this process on a P-V diagram.

i. Sketch cubes with volumes corresponding to the old and new volumes.

Answers to Selected Problems

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7. 40 N
8. a. 21,000 Pa b. Decreases to 61,000 Pa c. 5.8 km
9. a.8. 34 × 1023 b. 6. 64 × 10 −^27 kg c. 1600 m/s d. 744 kPa e. 4. 2 × 1020 or 0.0007 moles g. 0.00785 m^3