If a large moving train collides with a large bathtub filled with water on the track, then the train will smash

Question

through and destroy that bathtub in a spectacular fashion, all while continuing to move ahead. How is
Newton's Third Law, which says the force between the train and tub must be the same, still apply here?

Newton's Third Law states that the forces between them must be the same, but not the effects. So the tub
experiences the same force as the train, but has a much more visible reaction to that force

Newton's Third Law states that the amount force that is put on a mass causes it to accelerate. Since the
mass of the tub is split between the tub and the water, they both experience an acceleration from that
force

Newton's Third Law states that the tub will not move until there is a force upon it, so the train that is coming
provides that force which is what causes the reaction on the tub

There is no justification. Newton's Third law is not valid in the real world

Answer 1

Newton's Third Law states that for every action, there is an equal and opposite reaction. This means that if the train applies a force on the bathtub, the bathtub applies an equal and opposite force on the train.

In the scenario you described, the train colliding with the bathtub results in the tub being destroyed, but this does not violate Newton's Third Law. Here’s how it applies:

1. Equal and Opposite Forces: When the train collides with the bathtub, the force exerted by the train on the bathtub is equal in magnitude and opposite in direction to the force exerted by the bathtub on the train. Although the forces are equal, the effects can be very different due to the differences in mass and structural integrity between the train and the bathtub.

2. Acceleration and Mass: According to Newton's Second Law (F=ma), the acceleration experienced by an object is inversely proportional to its mass, given the same amount of force. The train is extremely massive compared to the bathtub and water. Therefore, even though both experience forces of equal magnitudes, the acceleration of the train will be negligible (and it will continue moving forward), while the bathtub and water experience a large acceleration leading to their destruction.

3. Visible Effects: The very different material properties and structural strengths of the train and the bathtub lead to different visible outcomes following the collision. The tub's structure cannot withstand the force exerted by the train, leading to visible destruction, whereas the train continues moving almost unaffected.

In summary, Newton's Third Law is still valid; the forces are indeed equal and opposite, but the resultant movements and effects differ significantly due to the vast differences in mass, structural integrity, and material properties of the two objects.