A box of mass m = 39.9kg sits on a rough horizontal surface. There is a coefcient of static friction ,u = 0.196 between the surface and the box. The box is subject to a force of magnitude F1 2 150.6N which pushes down and to the right making an angle of 9 = 31.6 degrees with the horizontal. The box is subject to a force of magnitude F2 which pushes to the left horizontally. (The input below will only mark answers correct if they vary by no more than 1% from the correct value.) What is the magnitude of the normal force the surface exerts on the box? lwl =i N