To convert kilometers per hour (km/hr) to meters per second (m/s), you can use the following conversion factor:
1 km/hr = 0.27778 m/s
To convert 126 km/hr to m/s, multiply the value by the conversion factor:
126 km/hr * 0.27778 m/s = 35 m/s
Therefore, 126 km/hr is equal to 35 m/s.