A child is sliding down a hill on a sled.
The child accelerated as the sled went down the hill.
Because of the forces of gravity, as an object moves down a sloped surface, it accelerates the longer it remains on the sloped surface. A hill is a sloped surface and the child is on the sled, so the child is accelerating with the sled as it moves down the hill.
exists e1 s1 x1 x2 x3.(a_down(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_slide(e1) & on(x2,x3) & n_sled(x3) & n_hill(x2) & n_child(x1))
exists e1 p1 x1 x2 x3.(n_hill(x3) & n_sled(x2) & n_child(x1) & exists e2.(down(e2,x3) & Actor(e2,x2) & v_go(e2)) & as(e1,p1) & Actor(e1,x1) & v_accelerate(e1))