* Acceleration is a change in velocity. Velocity is a combination of speed and direction. An object can accelerate by:

* Changing its speed: Think of a car speeding up or slowing down.

* Changing its direction: Think of a car turning a corner.

* Friction opposes motion. It's a force that acts against the relative motion of two surfaces in contact.

* Acceleration can be caused by forces other than friction. Examples include:

* Gravity: A ball falling from a height accelerates due to gravity.

* Thrust: A rocket accelerates due to the thrust from its engines.

* Electromagnetic forces: An electric charge accelerates in an electric field.

In Summary:

While friction can slow down or stop motion, it's not the only way an object can accelerate. Many forces can cause acceleration, and an object can even accelerate in the absence of friction.