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.

* Mass and Acceleration: The heavier an object is, the less it will accelerate when the same force is applied.

* Truck Comparison: A pickup truck is significantly lighter than a tractor-trailer truck. Therefore, the same force will produce a larger acceleration on the lighter pickup truck.