Here's how it works:

* Newton's Second Law of Motion: This law states that the acceleration of an object is directly proportional to the force applied to it and inversely proportional to its mass. In simpler terms, the more force you apply, the faster the object will accelerate. The heavier the object, the less it will accelerate with the same force.

* Relationship between force, mass, and acceleration: The formula for this relationship is: Force (F) = Mass (m) x Acceleration (a)

Here's an example:

Imagine pushing a shopping cart and a car with the same force. The shopping cart, being much lighter, will accelerate faster than the car because its mass is smaller.

In summary:

* Mass resists acceleration: A heavier object will be harder to get moving and harder to stop.

* Force is needed to change speed: To change the speed of an object, you need to apply a force.

* Acceleration is the result of force and mass: The greater the force, the greater the acceleration. The greater the mass, the smaller the acceleration.

It's important to remember that speed is just one aspect of motion. While mass affects acceleration, it doesn't directly control an object's speed. For example, a heavy object can be moving at a constant speed (like a train), while a lighter object might be accelerating quickly (like a speeding bullet).