A2L Item 088

• Description: Find the work done by a heated gas in a vertical piston.
• Goal: Problem solving
• Source: UMPERG
• Keywords: Energy, Problem Solving, Thermodynamics, Work

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The question for students:

A quantity of gas is confined to a cylinder. The cylinder is vertical and capped by a moveable piston of mass 2 kg and area 0.1 m². The gas is heated until the piston rises 20 cm. The amount of work done by the gas is most nearly

1. 4 J
2. 1 J
3. -20 J
4. 0.4 J
5. None of the above
6. Cannot be determined

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Commentary for teachers:

Answer

(1) This problem helps interrelate concepts from mechanics and thermodynamics. The work can be determined from the work done against the gravitational force.

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