Thread: A large truck collides head-on with a small compact car . ?

During the collision:

the truck exerts the same amount of force on the car as the car exerts on the truck.

why? thanks

The forces are equal and opposite. Imagine the truck as a vector of force 100 N, and the car as a vector (traveling the opposite direction) of force 50 N. Because these are vector quantities, you can add them together to get the force exerted onto each object (truck and car).

--------> + <---- = ---->
100 N + -50N = 50 N.

In this case, the car and truck would exert a force of 50 newtons upon each other.