Aboy wishes to throw a ball through a house via small openings, one in the front and the other in the back of the window, the second window being behind the the first. if the boy stands at a distance of 5m in front of the house and the house is 6m deep and if the opening in the front window is 5m above him and that in the back window 2m higher, calculate the velocity and the angle of projection of the ball that will enable him to accomplish his desire.