A projected-force-floor scan lowers the contact-line projection across three rows, checking when F = gamma * L * cos(theta) falls below the stated force floor. The arithmetic is exact only for the stated surface tension, line length, projection factor, floor threshold, and rows in the ideal wetting model. Real measurements add wetting/contact-angle variation, contamination, curvature departures, temperature, instrument calibration, finite precision, and measurement uncertainty.
A half-projection line source is scanned below, at, and above a useful pull floor. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Projected force is scanned by changing the line-force source
The two-surface line length is 2 m so the checked line-force source is 12 N. The projection factor stays 1 over 2. That leaves projected pull 6 N which is below boundary relative to the 12 N floor.
Fp=pF=21⋅12N=6N
Projected force is scanned by changing the line-force source
The two-surface line length is 4 m so the checked line-force source is 24 N. The projection factor stays 1 over 2. That leaves projected pull 12 N which is on boundary relative to the 12 N floor.
Fp=pF=21⋅24N=12N
Projected force is scanned by changing the line-force source
The two-surface line length is 6 m so the checked line-force source is 36 N. The projection factor stays 1 over 2. That leaves projected pull 18 N which is above boundary relative to the 12 N floor.