donkey is urged to pull a wagon. The donkey refuses, citing Newton's third law as a defence: the pull of the donkey on the wagon is equal to, but opposite the pull of the wagon on the donkey. The donkey asks, "If I can never exert a greater force on the wagon than it exerts on me, how can I ever start the wagon moving?" Reply to the donkey's objection and show why their claim is wrong. Hint: In your answer, make sure that the explanation is related to a physics principle covered in this unit.

donkey is urged to pull a wagon. The donkey refuses, citing Newton's third law as a defence: the pull of the donkey on the wagon is equal to, but opposite the pull of the wagon on the donkey. The donkey asks, "If I can never exert a greater force on the wagon than it exerts on me, how can I ever start the wagon moving?" Reply to the donkey's objection and show why their claim is wrong. Hint: In your answer, make sure that the explanation is related to a physics principle covered in this unit.