Answer: due to large momentum
Explanation:
The impact of the loaded truck is very large on a body coming in its way because of the momentum associated with truck. Truck has a huge mass which is responsible for its large momentum.
Momentum is the product of mass and velocity. Even though the velocity of truck is low but it's mass compensates for it to give large momentum. This large momentum can overwhelm any small body at rest or coming in its way.
