(Solved): Small ice cubes, each of mass 7.30g, slide down a frictionless track in a steady stream, as shown ...

Small ice cubes, each of mass $7.30\mathrm{g}$, slide down a frictionless track in a steady stream, as shown in the figure below. Starting from rest, each cube moves down through a net vertical distance of $h=1.50\mathrm{m}$ and leaves the bottom end of the track at an angle of $40.0^{?}$ above the horizontal. At the highest point of its subsequent trajectory, the cube strikes a vertical wall and rebounds with half the speed it had upon impact. If 25 . cubes strike the wall per second, what average force is exerted upon the wall?