Force and mass are directly proportional, meaning that as mass increases, the force required to accelerate it also increases. This is described by Newton's Second Law of Motion:

Force (F) = Mass (m) x Acceleration (a)

Let's break it down:

* Force: The push or pull that causes an object to change its motion.

* Mass: The amount of matter in an object.

* Acceleration: The rate of change of velocity (how quickly the object's speed or direction changes).

Here's how it works in practice:

* Pushing a small car: It takes less force to get it moving or stop it because it has less mass.

* Pushing a heavy truck: It takes significantly more force to get it moving or stop it because it has much more mass.

Key takeaway: The heavier the object, the more force you need to apply to achieve a given acceleration.