[例题]质量相等的甲、乙两小球,密度之比为ρ1:ρ2=2:3,将它们都放入足够深的水中,静止时两球所受的浮力之比为F1:F2=6:5,试求:(1)甲乙两球的体积之比。(2)甲乙两球的密度ρ1和ρ2。这是一条数量关系隐含于物理过程之中,很难直接求解的习题,可应用假设法讨论解答此题。 [Example] The equal mass of A and B balls, the density ratio is ρ1:ρ2=2:3, and they are all put into deep enough water. When the two balls are at rest, the ratio of buoyancy is F1:F2= 6:5, try: (1) The ratio of the volume of the two balls of A and B. (2) The density ρ1 and ρ2 of the two balls of A and B. This is an exercise that is implicit in the physical process and difficult to solve directly. The hypothesis method can be used to discuss and solve this problem.