Convert foot per minute to second per kilometer

Runners think in pace, minutes per kilometre or per mile, which is the reciprocal of speed: 5:00 min/km is 12 km/h, 6:00 min/km is 10 km/h, and 8:00 min/mile is 12.1 km/h. A 4-hour marathon needs 5:41 min/km, a 25-minute 5 km 5:00 min/km. Swimmers use seconds per 100 m; treadmills usually display km/h or mph, so the conversion comes up on every gym visit. Note that pace is the only unit here where a smaller number means faster.

Vertical speed in aviation is given in feet per minute everywhere, metric cockpits included: an airliner climbs at 1,500–3,000 ft/min after take-off and descends on final approach at about 700, while a glider's variometer shows lift in knots or m/s. US lifts and HVAC air velocities are rated in ft/min, a fast lift doing 1,000 ft/min (5 m/s). Feet per second is the unit of US ballistics (a 9 mm bullet leaves the barrel at about 1,150 ft/s) and of the handy rule that 60 mph is exactly 88 ft/s.