Hence equal and opposite reaction...
And, the velocity of an object remains constant unless acted upon by an external force.
Yeah, so a car going through a wall does not defy physics, because the car is acted upon by external force IE: a wall, that causes the car to slow down, and by the force of which the car hit the wall, causes the car to sustain considerable damage.
Laws of motion are physics aren't they? Look, I dunno, I'm twelve.