Meters per second (m/s) is the SI base unit for speed and velocity, representing the distance in meters traveled during one second. It is the standard unit in physics, engineering, and scientific research, used to describe everything from falling objects to fluid flow rates. One meter per second equals exactly 3.6 kilometers per hour or approximately 2.237 miles per hour.

Mach (Ma) is a dimensionless speed unit representing the ratio of an object's speed to the speed of sound in the surrounding medium. At sea level under standard conditions, Mach 1 equals approximately 343 meters per second or 1,235 kilometers per hour, though this varies with altitude and temperature. Supersonic aircraft travel above Mach 1, while hypersonic vehicles exceed Mach 5.