Here's why:

* Speedometer measures speed: A speedometer measures how fast a vehicle is moving, typically in units like miles per hour (mph) or kilometers per hour (km/h).

* Force is a different concept: Force is a push or pull that can cause a change in motion. It is measured in units like Newtons (N).

While speed and force are related (force can cause acceleration, which is a change in speed), they are distinct concepts.

Think of it this way:

* Speedometer: Tells you how fast you're going.

* Force: Tells you how much effort is being applied to make you go faster or slower.