Fy is the reaction force from Plate Y. What Statement best describes the action and reaction forces on the plates? Tectonic plates

According to Newton's third law of motion, the reaction force is equal to the action force.

Explanation:

Newton's third law of motion states that for every action there is an equal and opposite reaction. This means that if one object exerts a force on a second object, the second object exerts an equal force in the opposite direction. When Plate X pushes on Plate Y with the action force (Fx), Plate Y must push back with an equal force (Fy).

Therefore, the best explanation is that according to Newton's third law of motion, the reaction force is equal to the action force.

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.