what is the most suitable unit to measure the length of a car key
That depends what aspect of the car you want to measure: for example its length, volume, mass, weight, color, etc.
It is a kilonewton.
The meter.
miles or kilometers
I would use centimeters.
It depends on what you are measuring the width of. Different units and different tools would be appropriate for a hair, a car or a galaxy.
Meter
mm, cm or m.
Scientists use Kilometers to measure distance traveled by a car
Meters
It is a kilonewton.
meter A kilometer is 1000 meters.
kg. (kilograms), or tons (thousands of kg.).
Distance travelled against time. For instance, miles per hour (MPH) to measure the speed of a car.
feet The meter (m) is the international unit (in SI) for length.
That is optional. The best unit of measurment would probably be tons.By:Donny Heitler
Centimetres and millimetres. In past times, it would have been feet and inches.
To measure a car's length, I would try yards or feet. Maybe both. It mostly depends on the legnth of a car. A stretch limo would use yards while a VW Bug would probably be feet. For an average car, though, yards.