A particle A of mass m initially at rest slides down a height of 1.25 m on a frictionless ramp, collides with and sticks to an identical particles B of mass m at rest as shown in the figure.

Then, particles A and B together collide elastically with particle G of mass 2m at rest. The speed of particle G after the collision with combined body (A+B) would be (Take, g`=10 ms^(-2))`