mph/s

mile per hour per second

Accelerationexact by definition

A mile per hour per second is exactly 0.44704 m/s². It is the American form of the same idea: a vehicle that gains 10 mph every second is accelerating at 4.47 m/s², about 0.46 g. Transit authorities specify service acceleration and braking rates in mphps.

Watch out: Standard transit comfort limits sit near 3 mphps for acceleration and service braking, with emergency braking higher. Exceeding them is not a mechanical limit but a standing-passenger one.

1 mph/s 0.44704 m/s²