Under 14 CFR Part 107, what is the maximum groundspeed for a small unmanned aircraft?

Why →Under 14 CFR § 107.51(a), the maximum groundspeed for a small UAS is 87 knots (100 mph). This applies at all times during flight operations.

The trap →"100" looks like the clean round number to pick, but 100 knots is 115 mph, well above the limit. The magic number is 87 knots.

Field note →The speed limit is a highway number, 100 mph. The knot figure, 87, is the oddball to memorize.