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1 由一道题引起的讨论对高中热学一道竞赛练习题,学生有两种不同的解答。 [题目] 如图1所示,容积为V_0的绝热密闭容器,盛有理想气体,温度为T_0,压强为p_0。轻质绝热活塞在外力作用下,由容器最右端A处,缓慢地移到中央B处,然后释放活塞,活塞即由B处返回A处,活塞与容器的摩擦不计,试定性比较气体最终状态温度T与初始状态温度T_0,及最终压强p与初始压强p_0的大小,并简要说明理由。 [解答1] 第一过程,活塞由A处移至B处,外界对气体作功,系统绝热,由热力学第一定律知,气体内能增大,温度升高,又由理想气体状态方程(pV)/T=常量知,
1 Discussions Caused by a Problem Students have two different answers to the high school thermal competition exercises. [Title] As shown in Fig. 1, a thermally insulated, airtight container with a volume of V_0 contains an ideal gas with a temperature of T_0 and a pressure of p_0. Under the action of external force, the lightweight thermal insulation piston slowly moves from the rightmost end A of the container to the center B, and then releases the piston. The piston returns from the B to the A position. The friction between the piston and the container is not counted. The temperature T and the initial state temperature T_0, and the final pressure p and the initial pressure p_0, and briefly explain the reason. [Solution 1] In the first process, the piston moves from point A to point B. The outside world performs work on the gas and the system is adiabatic. Knowing from the first law of thermodynamics, the internal energy of the gas increases, the temperature increases, and the equation of state of the ideal gas ( pV)/T=Constant,