two identical balls moving in opposite direction with speed 20 m/s and 25 m/s undergo head on perfectly inelastic collision. The speed of combined mass after collision is .... (1) 20 m/s(2) 22.5 m/s(3) 25 m/s(4) 2.5 m/s.by mistake I put this question in art subject sorry but it is of Physics.... Created by shruti1618. Art

From conservation of momentum we can say that, total initial momentum of the two masses= total finial momentum of the combined masses. Since the masses are same hence the equation can be written as- 20m – 25m= 2vm => -5m=2vm => v= -2.5ms-1. Hence the speed of the combined masses will be 2.5ms-1 in the direction of the body moving with 25ms-1 initially