Here's why:

* Newton's Second Law of Motion: This law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

* Formula: This can be expressed as: F = ma where:

* F = force

* m = mass

* a = acceleration

* Interpretation: If the force (F) is constant, then a smaller mass (m) will result in a larger acceleration (a).

Example:

Imagine pushing a small car and a large truck with the same force. The car will accelerate much faster than the truck because it has less mass.