When someone throws a ball the action force is the person pushing on the ball. what is the reaction force?

Reaction force is on the person in backward direction

Explanation:

When we throw the ball then the action force is on the ball due to which ball is pushed away with certain velocity.

Here the reaction force is of same magnitude but in opposite direction on us due to which we pushed back.

Here we do not move in backward direction because here the force on us is counterbalanced by the friction force of the ground due to which we can maintain our position easily.

So here we can say that action and reaction pair are the two forces of equal magnitudes but opposite in direction.

One force here is action force on ball then the reaction force is on the person who throw the ball