If the action force is the boy pushing on the ball, what is the reaction force? | Which way will the boy on the skateboard move?

By Newton’s third law, forces come in equal and opposite pairs. If the boy pushes on the ball, the ball pushes back on the boy, so choice B, “the ball pushing on the boy,” is the reaction force. The boy and skateboard will move in the direction opposite to the force the boy applies to the ball.

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