payne1000 wrote:
Newton's Third law says the falling top section should have received an equal and opposite reaction. There was none. That means all the resistance of all those floors underneath the top sections had been removed. The only force which could remove that resistance is powerful explosives. Watch how smoothly the top section comes down.
No equal and opposite reaction happened.
Newton's 3rd Law is stated thus: For every ACTION, there is an equal and opposite REACTION. We good so far?
Newton's third law of motion is naturally applied to collisions between two objects. In a collision between two objects, both objects experience forces that are equal in magnitude and opposite in direction. Such forces often cause one object to speed up (gain momentum) and the other object to slow down (lose momentum). According to Newton's third law, the forces on the two objects are equal in magnitude.
While the forces are equal in magnitude and opposite in direction, the accelerations of the objects are not necessarily equal in magnitude. In accord with Newton's second law of motion, the acceleration of an object is dependent upon both FORCE AND MASS. Thus, if the colliding objects have unequal mass, they will have unequal accelerations as a result of the contact force that results during the collision.In the game of golf, consider the collision between the club head and the golf ball. When the club head of a moving golf club collides with a golf ball at rest upon a tee, the force experienced by the club head is equal to the force experienced by the golf ball. Most observers of this collision have difficulty with this concept because they perceive the high speed given to the ball as the result of the collision. They are not observing unequal forces upon the ball and club head, but rather unequal accelerations.
Both club head and ball experience equal forces, yet the ball experiences a greater acceleration due to its smaller mass. In a collision, there is a force on both objects that causes an acceleration of both objects. The forces are equal in magnitude and opposite in direction, yet the least massive object receives the greatest acceleration.Consider the collision between a moving cue ball and an eight ball that is at rest in the sport of table pool. When the cue ball collides with the eight ball, each ball experiences an equal force directed in opposite directions. The moving cue ball experiences a force that causes it to slow down; the eight ball experiences a force that causes it to accelerate. Since the two balls have equal masses, they will also experience equal accelerations. In a collision, there is a force on both objects that causes an acceleration of both objects; the forces are equal in magnitude and opposite in direction.
For collisions between objects of equal mass, each object experiences the same acceleration.
Consider the collision between the windshield in a 3000 pound car traveling 60mph and a 1 gram bug flying in the opposite direction at 5 mph. When the bug collides with the windshield, both the bug and the windshield experience equal and opposite forces, yet the bug experiences a greater acceleration due to its considerably smaller mass. In a collision, there is a force on both objects that causes an acceleration of both objects. The forces are equal in magnitude and opposite in direction, yet the least massive object receives the greatest acceleration. Therefore the 1 gram bug gets the worst of the deal, it gets accelerated in the opposite direction it was flying. The windshield hardly felt a thing, in never slowed down a fraction. All it needed was some cleaning.
Take whatever time you need and ponder this concept. And apply it to the collapse of a WTC tower.
Consider the North Tower.
Here are some hints.
1) The mass above the point of collapse initiation weighed 67,500 tons.
2) The 67,500 ton mass DID NOT collapse on all the floors below instantaneously. It hit ONE FLOOR at a time. (Each floor had a mass of approximately 4500 tons.)
3) Obviously, the 67,500 ton mass and the 4500 ton mass of the first floor hit WERE NOT of equal mass.
4) As the tower collapsed, the falling mass gained both mass and momentum.
5) As the collapsing tower gained more mass and momentum, the inequality of the opposing masses increased. It was almost like a bug hitting a windshield.