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题目:有密度分别为ρ_1和ρ_2的水溶液各m千克,只用这两种溶液,最多可配制成密度ρ_混=1/2(ρ_1+ρ_2)的水溶液多少千克?已知ρ_1>ρ_2,(1996天津市考题)分析:本题属于用混合溶液的密度公式求相关物理量极值的综合题,但用常规方法仅能列出方程组,且未知数的个数比方程组的个数多一个,导致解的不确定性.但将其中的一个未知数固定,解另几个未知数的方程组,即可将结
Title: There are m kilograms of aqueous solutions with densities of ρ_1 and ρ_2 , respectively. Using only these two solutions, it can be formulated as a solution with a density ρ_mix=1/2 (ρ_1+ρ_2) in kilograms. Known ρ_1>ρ_2, (1996 examination questions in Tianjin) Analysis: This question belongs to the comprehensive problem of using the density formula of the mixed solution to find the extreme value of the relevant physical quantity, but only the equations can be listed by conventional methods, and the number of unknowns is one more than the number of equations. Causes the uncertainty of the solution. But by fixing one of the unknowns and solving a few unknown equations, you can