Гидродинамика

IMPACT OF TWO BALLS, OE WHICH ONE IS FLOATINC IN A LIQUID The problem considered in this article is as follows: a ball of mass m. fallingf vertically with velocity w, impinges o n a ball, of mass m' floating in a liquid. The density of ball m i s equa l to half of the density of the liquid, its radius is r, and i t s c en t r e coincides with the centre of the semi-spherical vessel of r a d i u s Гп filled to the top with,liquid. To determine the ve l oc i t i e s u and n of the balls after the impact. Prof. Joukowsky finds the impulsive .pressure at the t i m e of impact (formulae 7, 8), hence, by applying the equation o f acti ­ vity and the Principle of Energy (in the case of an elastic i m p a c t ) , obtains for velocities и and и formulae (11) and (14), wi ch differ from the usual formulae of impact of balls only i n that in the case considered the mass of the floating ball m i s r e p l a ­ ced by m ' -|~ Рч where ' J - is given by formula (9).