What is the maximum force that can be supported on a surface in equilibrium? In order to find out, we will need to first consider what forces are acting at the location of interest. The only forces that act there are gravity and normal force. Let’s take them one by one: The magnitude of the gravitational force (Fg) is determined as follows: Fg = mgsinθ where m is mass, g is acceleration due to gravity, and θis angle between height and horizontal plane. We know from geometry that if θis 90 degrees then sinθ=1 so Fg=mg which means it equals your weight. If you want to calculate for other angles use this online calculator (http://functions.wolframalpha.com/euler_angles/.) The magnitude of the normal force (Fn) is determined as follows: Fn = Fg – Fr where Fg is gravitational, and Fr is friction acting on a surface. We know from physics that if you are standing in equilibrium then there will be no acceleration forces which means we can say that θ=90 degrees so sinθ=-cosθ or cosθ=(-sinθ)/(cosθ). Rearranging things gives us that Fn = mg – μmgR where Ris radius from center of mass to contact point with the ground, μis coefficient of kinetic friction between surfaces, and gcoefficient of gravity near Earth’