A 2 lb particle is sliding along a at horizontal frictionless surface with a velocity of 10 ft/s along the x-axis. When the particle is 20 ft from a wall which is perpendicular to the x-axis, it explodes into two identical pieces. One piece A, hits the wall at a y-coordinate of 5 ft while the other B hits the wall at a y-coordinate of -10 ft. Determine the impulse on particle A by the explosion, the velocity of A relative to B at the instant immediately after the explosion and the time dierence between when A hits the wall and B hits the wall.