Bugatti Veyron top speed: 435 km/hr
Most countries use the Metric System, which uses the measuring units such as meters and grams and adds prefixes like kilo, milli and centi to count orders of magnitude.
121 m/s
1.21 * 102 m/s (scientific)
120.83 m/s (engineering)
In the USA and UK, the older Imperial system is used, where things are measured in feet, inches and pounds.
435,000 m/hr
396 ft/sec
3,600 secs
1.0 hrs
3.6 * 103 sec(s)
60 min(s)
1 hr(s)
435,000 meter
1.43 * 106 ft
475.72 * 103 yard
435 * 103 m
435 km
270.3 mile
234.88 nautical mile