21 centimeters per second equals 21 centimeters per second |
21 centimeters per second equals 0.688976378 feet per second |
21 centimeters per second equals 0.7559939521 kilometers per hour |
21 centimeters per second equals 0.4082108701 knots |
21 centimeters per second equals 0.21 meters per second |
21 centimeters per second equals 0.4697566213 miles per hour |