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在斯特列可夫等著的《普通物理习题汇集》中,有这样一道题:质量为M的反冲式轮船用一具抽水机来发动.抽水机把水由河中吸进来,又由船尾把水喷出去.水流对于船的速度是不变的,并且等于u.每秒钟被抽水机喷出去的水的质量也是不变的,并且等于μ.(1)把船的速度v表为时间的函数;(2)把系统的效率η表为u和v的函数.研究在效率最大时的关系式.抽水机的摩擦力和水对于船的运动阻力可不必考虑. 这道力学题不但综合性较强,而且概念性也较强.《普通物理习题汇集》中,给出了简单的解答.我们认为书中的解答可能有问题,有必要提出我们的看法,供大家讨论、鉴别.
In the “Ordinary Physics Exercises” by Strekoff et al., There is such a problem: A recoil ship of mass M is powered by a pump that draws in water from the river and aft the water The flow of water is constant for the speed of the ship and is equal to u The mass of water squirted by the pump per second is also constant and equal to 1. (1) The speed v of the ship is expressed as time (2) The efficiency of the system η as a function of u and v. To study the relationship between the efficiency of the maximum. Pump friction and water resistance to the movement of the ship may not have to consider this road mechanics is not only comprehensive Strong, and conceptual strong. “General Physics Exercises”, given a simple answer. We think the book may have problems in the solution, it is necessary to put forward our views for your discussion and identification.