Here's why:

* Machines are designed to amplify or change the direction of force. They don't create energy; they simply transfer it.

* Force is a push or pull. When a machine exerts force, it's applying a push or pull to an object.

* Examples:

* A lever exerts force to lift a heavy object.

* A pulley system exerts force to lift a weight.

* A car engine exerts force to move the car.

Let me know if you'd like more detail on any of these!