θ = 1,253 rad

A = ((50mm^2)/2) * (( 1,253rad )-sin( 1,253rad )) = 379mm^2

The maximum force transferred is therefore the yield strength of the frame times the area under the hoof. Since it is the "Golden Oak" library, let us use that material for the frame. Oak has a maximum yield strength of σ = 60 MPa (N/mm^2).



Maximum force is therefore:





F = σ * A = 60 N/mm^2 * 379mm^2 = 22 740 N.



Observation shows that the mare's weight is not enough to cut the vine. Only when she uses her famous earth pony strength does the window slam shut. If we assume that her legs are 0,5m long, each of her forelegs must muster a moment of:





M= F*L = 22740N * 0,5m = 11370 N*m