Here's why:

* Newton's Laws of Motion: Newton's Second Law of Motion tells us that a force is directly proportional to the mass of an object and its acceleration. Acceleration is the rate of change of velocity. Velocity includes both speed (how fast something is moving) and direction.

* Examples:

* Pushing a box: Pushing a box causes it to accelerate, changing its speed.

* Throwing a ball: Throwing a ball applies a force that changes its direction and speed.

* Turning a car: The steering wheel applies a force that changes the car's direction without necessarily changing its speed.

Let me know if you'd like to explore specific examples in more detail!