Two 20 kg spheres are fixed in place on a y axis, one at y = 0.40 m and the other at y = -0.40 m. A 10 kg ball is then released from rest at a point on the x axis that is at a great distance (effectively infinite) from the spheres. If the only forces acting on the ball are the gravitational forces from the spheres, then when the ball reaches the (x, y) point (0.30 m, 0), what are

(a) Its kinetic energy and

(b) The net force on it from the spheres, in unit-vector notation?