a $0\mathrm{.}250$kg object is slid on a frictionless surface into a dark room, where it strikes an initially stationary object with mass of $0\mathrm{.}450$kg$.$ the $0\mathrm{.}250$kg object emerges from the room at an angle of $45$ degrees with its incoming direction. the speed of the $0\mathrm{.}250$kg object is originally $2\mathrm{.}00$m$/$s and is $1\mathrm{.}50$m$/$s after the collision. confirm that the collision is elastic. what is the ratio of the objects' kinetic energies?