The discussion revolves around the implications of Newton's Third Law in the context of car crashes, specifically comparing the effects of two cars colliding at the same speed versus one car crashing into a wall at a higher speed.
Some participants have provided insights into the forces involved in collisions, suggesting that the forces experienced by the cars differ based on the scenario. There is ongoing exploration of how velocity and mass influence the forces during a crash, with some participants questioning how varying masses would affect the outcomes.
Participants are considering the assumptions regarding the strength of the wall and the conditions under which the cars come to a stop. There is also uncertainty about the effects of differing masses on the collision dynamics.
giokrutoi said:what do you mean in better
Of the 2 cars, each exerts a lesser force since their collision velocity is less. Whereas if the car crashed into the wall, the wall would exert a stronger reaction force on the car because of the increased velocity at the point of impact? Is this true?RUber said:If there are two cars, each one will be subjected to the other's opposing force. If there is one car, and you assume the wall is strong enough to fully stop the car, it will be subjected to the larger resisting force of the wall.
Let's say that ##F_1## is generated by car 1 and ##F_2## is generated by car 2, then ##F_1= -F_2## for a perfect head-on crash ending in full stop.
Let's say that ##F_3## is generated by the fast (100km/hr) car 3 and ##F_4## is generated by the wall, then ##F_3= -F_4## for a car-on-wall crash ending in full stop.
RUber said:That's about right. I would assume that in all cases, it takes the same time for the cars to come to a stop. Thus, acceleration would be proportional to velocity.
More velocity brought down to zero velocity over the same time results in more force.
There are finer points when you deal with impulses and collisions, but as it refers to F=ma, this is the most fundamental explanation.
More velocity, same mass, same time => more force.