本题目来源于试卷: gc textbook chapter 13 temperature and kinetic theory，类别为 通用国际物理
[问答题]
When a gas is rapidly com k; 9srjre26 wa:45io7mebw jk d 8.+4jiu4n zhgih6xtpressed (say, by pushing down a piston), its temperature increases. When a gas expandnu xdh6gizt44h. 8ij +s against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noting what happens to the momentum of molecules when they strike the moving piston.
参考答案: When
a small mass object collides with a stationary massive object, the speed of the
small mass is not changed. But when a
small mass object collides with a massive object moving in the opposite
direction, the speed of the small object increases. For example, a tennis ball of a given speed
that is struck with a racket will rebound with a greater speed than a tennis
ball of the same speed bouncing off a wall.
So as the gas molecules collide with the piston that is moving toward
them, their speed increases. The
microscopic increase in molecular speed is manifested macroscopically as a
higher temperature.
In a similar fashion, when the molecules
collide with a piston that is moving away from them, they rebound with a
reduced speed compared to their initial speed.
This lower speed is manifested macroscopically as a lower temperature.
本题详细解析:
暂无
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