Figure P21.1 shows a gas confined to a cylinder fitted with a movable piston. The cylinder is immersed in a tank of water that acts as a thermal reservoir, so that the temperature of the gas never changes.

(a) With the system defined as the gas, draw an energy input-output diagram for the system as sand grains are slowly removed from the top of the piston and the piston rises.

(b) Does the system's energy change? Does its entropy change?

(c) Is this a steady device?

Data from Figure P21.1

Transcribed Image Text:

T-T P Sand is removed slowly. TR T-TL V>V P,