Name and state the action and reaction in the following cases:
$(i)$ Firing of a bullet from a gun.
$(ii)$ Hammering a nail.
$(iii)$ $A$ book lying on a table.
$(iv)$ Moving rocket.
$(v)$ $A$ person moving on the floor.
$(vi)$ $A$ moving train colliding with a stationary train.

(N/A) $(i)$ When a bullet is fired from a gun,the force exerted on the bullet is the action,and the recoil force experienced by the gun is the reaction.
$(ii)$ When a nail is hammered,the force exerted by the hammer on the nail is the action,and the force exerted by the nail on the hammer is the reaction.
$(iii)$ When a book is placed on a table,the weight of the book acting downwards on the table is the action,and the normal force exerted by the table upwards on the book is the reaction.
$(iv)$ In a moving rocket,the force exerted by the rocket on the exhaust gases is the action,and the force exerted by the gases on the rocket is the reaction.
$(v)$ When a person walks,the force exerted by the person's foot pushing the ground backwards is the action,and the frictional force exerted by the ground on the foot in the forward direction is the reaction.
$(vi)$ When a moving train collides with a stationary train,the force exerted by the moving train on the stationary train is the action,and the force exerted by the stationary train on the moving train is the reaction.