Small car colliding with large truck?

Question

A small car collides with a large truck. Why do both vehicles experience the same magnitude of force? Wouldn't the large vehicle experience less force than the small one?

Answer 1

To say it another way: If the forces were not equal, it would mean that some other external force was being applied to the system. If the 2 vehicles are the only objects in the game, there is no way to have another external force.

Newton says: For any force applied to a mass, there is an equal and opposite reaction (force). You push on a rock with 1 # of force, and it pushes back on you--also with 1#.

Answer 2

Yes the larger vehicle experiences less acceleration than the smaller one. And both of the vehicles experience the same force.

Force is an external agency that acts upon a body. Remember Newton's third law that says every action has equal and opposite reaction--so if the car experiences a force of 100N from the truck, the truck will also experience a force of 100N from the car. So both of them experience the same force. However, because the mass of the truck is larger, so the truck will experience less acceleration (since F = m * a, so we get a = F / m).