The law of acceleration, also known as Newton's Second Law of Motion, doesn't directly "change speed," but it describes the relationship between force, mass, and acceleration. It explains how a force applied to an object causes it to accelerate, which in turn can change its speed.

Here's how it works:

* Force: A push or pull applied to an object.

* Mass: The amount of matter in an object.

* Acceleration: The rate of change of velocity (speed and direction).

Newton's Second Law states:

Force = Mass x Acceleration (F = ma)

How it affects speed:

* Positive acceleration: If a force is applied in the same direction as the object's motion, it will increase its speed.

* Negative acceleration (deceleration): If a force is applied in the opposite direction to the object's motion, it will decrease its speed.

* Zero acceleration: If the net force acting on an object is zero, it will maintain its current speed (either at rest or in constant motion).

Example:

Imagine pushing a shopping cart. The force you apply is the "F". The cart's mass is the "m". The result is an acceleration "a" that causes the cart to speed up.

In conclusion:

The law of acceleration doesn't change speed directly, but it describes how force affects the acceleration of an object. This acceleration, in turn, leads to changes in the object's speed, whether it's increasing, decreasing, or staying constant.