Here's why:
* Speed is a measure of how quickly an object changes its position over time.
* Speedometers are designed specifically to measure and display the speed of a vehicle.
There are also other instruments that can measure speed, but they might be more specialized depending on the context:
* Anemometer: Measures wind speed
* Tachometer: Measures the rotational speed of an engine
* Radar gun: Measures the speed of moving objects, often used by law enforcement
So, while a speedometer is the most common instrument for measuring speed, there are other tools depending on what you want to measure.
